My sprocket experiences on a GS500.

[twocool]

YES! YES! YES!....

The manifold pressure is different animal than the venturi pressure in the carb....

Basically the carb works on air flow....more air flow=more air fuel mixture...the same ratio of air /fuel  but just more of it...

yeah, carbs are a bit more complicated than that due to the idle, midrange and high speed...different jets etc....

But basically the carb takes the air, and adds the correct amount of fuel..based on air flow(through the venturi)...not throttle setting or RPM...

BTW...The use of the word "vacuum" in engines bugs me....yes it is widely used, but technically incorrect.....

You have manifold PRESSURE...not vacuum....the manifold pressure is typically lower than ambient air pressure...but it is still pressure...it is not a negative value...it is a positive pressure..

Typically normal atmosphere is 29.92 in hg PRESSURE....

A running  engine might have say, 25 in hg manifold pressure...this is a pressure, just less pressure than ambient...

The pistons do not "suck" the air in....the air is PUSHED in by atmospheric pressure....

In a turbo or supercharged engine, the air is further pushed in by the turbo or supercharger, and manifold pressures are typically HIGHER than ambient...but even in this case the fuel air ratio remains basically the same...just a LOT more of it going into the cylinders....so more power!

Essentially, manifold pressure is an indication of "power"...so 25 in hg manifold pressure would indicate more power than 22 in hg...


BUT.....high manifold pressure and low RPM is really hard on an engine..

There is a lot of reading available on the internet...wiki manifold pressure (vacuum)...also wiki the difference between manifold pressure(vacuum) and venturi pressure (vacuum)

Cookie










Fuel is drawn from the fuel bowl by the Venturi Effect, not vacuum.


[/quote]

[twocool]

Fuel is not fed to the engine by gravity....in the GS500 fuel is fed to the carb float bowl by gravity...

Think of the float bowl as just a tiny little fuel tank....

Air flows through the carburettor throat....it passes through the VENTURI, the venturi is a narrowed section of the throat....since it is narrow...the air flow speeds up to get through...

Bernoulli principal says total pressure remains the same....so ...when the air speeds up, the DYNAMIC pressure is increased, but since total pressure must remain the same, the STATIC pressure decreases.....so fuel is "pushed" through the jet...Higher pressure outside the jet...lower pressure in the venturi ...

If more air goes through the venturi...then more pressure difference...so more fuel goes through the jet...

The throttle is what you might consider a "restrictor"...it holds back the airflow...so less airflow...less fuel....less power...

Some examples:

lets say you are going DOWN a step hill.....what are you going to do with the throttle?

Most likely you're gonna CLOSE the throttle.....so the airflow is restricted....so the manifold pressure is low....the flow through the carb venturi is also low, because it is restricted by the throttle closed......so the engine is making very little power....but you don't need power, because you are going down hill....even though the RPM can be very high....you are making little power....low manifold pressure....throttle restricting air flow....


Now you get to the bottom of the hill, and go UP the next hill...what is the first thing you need to do?

OPEN the throttle....(maybe down shift too)...but when you open the throttle, you remove the restriction to the airflow in the carb....more airflow, more venturi effect, more gas....and HIGHER manifold pressure....more power is created...

YES, and air filter has a slight restriction to air flow...but this happens way before you get to the venturi...but this is why some guys want a low restriction air filter....less restriction in the air filter means more air flow through the carb is possible...more air means more gas means also higher manifold pressure means more power....

The trouble with free flowing filters is that they do not filter all that well...the performance increase is nearly imperceptible(on gs 500), while the potential damage to the engine is great....


Cookie












Which part?  I'm not trying to challenge what you say, I just want to understand better.  The fuel is fed by gravity, yes?  By decreasing the size of the line, the velocity is increased at the jet, yes?

I'm very confident that my filter pressure drop portion is correct, but I'm unsure of the correlation between air flow and rpm and throttle "demand".  How does it work, exactly?

Roaring via Tapatalk.
[/quote]

[Old Mechanic]

I agree with two cool, especially his point about manifold pressure. Atmospheric pressure is due to the 100 mile high column of air that is trying to crush everything at 14.7 PSI. That's many tons of force on the surface of your body.

Where I disagree is running an engine at higher loads will cause premature wear. Maintaining a given speed takes only a small percentage of the power capacity of an engine but contributes greatly to efficiency in MPG.

The point where you are "lugging" an engine is when adding throttle imput does not result in increasing speed. My GS pulls fine from 30 MPH in 6th, with stock gearing, but not from 25 MPH.

If your goal is to maintain speed then use 6th for maintaining speed, down to 25 MPH, BUT if you need to accelerate, THEN you must choose the appropriate gear for the rate of acceleration desired sometimes from 6th down to even 2nd in extreme cases.

If you do not choose the right gear and try to accelerate in a higher gear, then prolonged operation under those circumstances will cause increased wear and tear.

I am a hypermiler, but not so extreme that it impedes the flow of traffic or aggravates other driver-riders unless they are agressive tailgaters or such, then I just get away from them as they are stupid and will cause an accident that injures or kills me and then they, the casue of the accident, will drive away leaving me to bleed out and die.

regards
mech

[Dr.McNinja]

I agree with two cool, especially his point about manifold pressure. Atmospheric pressure is due to the 100 mile high column of air that is trying to crush everything at 14.7 PSI. That's many tons of force on the surface of your body.

Where I disagree is running an engine at higher loads will cause premature wear. Maintaining a given speed takes only a small percentage of the power capacity of an engine but contributes greatly to efficiency in MPG.

The point where you are "lugging" an engine is when adding throttle imput does not result in increasing speed. My GS pulls fine from 30 MPH in 6th, with stock gearing, but not from 25 MPH.

If your goal is to maintain speed then use 6th for maintaining speed, down to 25 MPH, BUT if you need to accelerate, THEN you must choose the appropriate gear for the rate of acceleration desired sometimes from 6th down to even 2nd in extreme cases.

If you do not choose the right gear and try to accelerate in a higher gear, then prolonged operation under those circumstances will cause increased wear and tear.

I am a hypermiler, but not so extreme that it impedes the flow of traffic or aggravates other driver-riders unless they are agressive tailgaters or such, then I just get away from them as they are stupid and will cause an accident that injures or kills me and then they, the casue of the accident, will drive away leaving me to bleed out and die.

regards
mech

Excessive load on the engine will cause premature wear. It's simple math. The harder you make your engine work to do anything, the more each part has to compensate for. If you maintain your RPMs engine load will remain effectively constant. Just because it's constant doesn't mean that it isn't causing damage. Especially if you're going 30 mph in a gear designed for 45-50 mph (overdrive). I'd imagine piston rings would be some of the first parts to go.

Running out to 6th gear on a motorcycle at 30 mph seems like a hazard. I'd imagine you have to go almost WOT to go anywhere. How are you not lugging the engine everywhere you go? How are you supposed to get out of being merged into if you have to pound down 4 gears to get any ponies to the rear wheel? On stock gearing I run my gears out and shift as late as possible and still get better fuel economy than anything but a geo. However, my bike will lug in 6th anywhere below 45mph and there is a significant drop in torque, which means I wont be able to react to hazards. Running richer with dynojet stage 3, pods, yoshi exhaust, and aggressive throttle I still average ~45 mpg. Whats the point?

I understand the challenge of hypermiling and how it could be fun, but it seems like a waste of time on something that is already incredibly efficient even raced out. With fuel so cheap, you're literally saving a few dollars here or there, which will go back into your bike because hypermiling is likely much harder on the oil/gears/drivetrain. Especially if you're following the whole turn your bike off at a stoplight thing, which will absolutely destroy the already fickle starter in the gs500. Even worse if you've rejetted the bike to be extremely lean, because all newer GSes have garbage oil coolers that do almost nothing for the overheating problem.

[twocool]

Lugging an engine....well at what point one is lugging is up for debate....

The case given of relative low speed in 6th gear...BUT at LOW throttle setting...is NOT lugging...

Trying to go up a hill, at low speed, in 6th gear, and using full throttle IS lugging....and does cause high loads on engine components, and can cause wear and damage...

overheating...detonation....low oil pressure are just a couple of problems.....con rods, rod bearings, pistons all are under high load....Ever try to drive an older carb car up a hill in too high a gear?  Hear the sound like marbles bouncing around in the engine?  That's lugging...and that's stress, and wear and potential damage...

Ever try to ride your ten sped bike up a steep hill in top gear?  Feel the strain in your muscles and knees?  That's lugging...Shift to low gear and you "spin" your way up with far less stress...

That being said...from the GS500 owners manual...

Shift Schedule:

Upshift schedule:

1-2....12 MPH
2-3....19 MPH
3-4....25 MPH
4-5....31 MPH
5-6....37 MPH

Downshift schedule:

6-5.... 25 MPH
5-4.... 19 MPH
4-3.... 12 MPH


While these numbers are certainly possible, and apparently do-able without damage...IF you drove like this, like a little old lady, you would be using about 5 HP of the 40 or so available...your mileage would be great!...the bike would fell like a wet noodle, and riding would be no fun at all...

The GS 500 has many gear ratios (6)... the engine is tolerant of wide RPM range...the gears are close and have wide overlap...all this makes for a very "drivable" bike...


Hypermiling on a GS500....

Really?  so what mileage do you regularly get?

If I ride conservatively...no WOT...smooth easy accelerations...steady long runs at 50 ~55 MPH....I get upper 60's to 70 MPG.....

If I drive in a more "fun" way...I get lower 60's


If I drive like a nut....I get upper 50's

No need to change gearing.....no need to drive like an old lady....no need to take some of the risks in hyper mileing...(drafting) turning engine off down hill etc..)

BTW...Mr. Lee is so full of misconceptions, and lack of understanding..and ignorant of basic physics, that it would take a book to correct all of them!



Cookie











mech
[/quote]

Excessive load on the engine will cause premature wear. It's simple math. The harder you make your engine work to do anything, the more each part has to compensate for. If you maintain your RPMs engine load will remain effectively constant. Just because it's constant doesn't mean that it isn't causing damage. Especially if you're going 30 mph in a gear designed for 45-50 mph (overdrive). I'd imagine piston rings would be some of the first parts to go.

Running out to 6th gear on a motorcycle at 30 mph seems like a hazard. I'd imagine you have to go almost WOT to go anywhere. How are you not lugging the engine everywhere you go? How are you supposed to get out of being merged into if you have to pound down 4 gears to get any ponies to the rear wheel? On stock gearing I run my gears out and shift as late as possible and still get better fuel economy than anything but a geo. However, my bike will lug in 6th anywhere below 45mph and there is a significant drop in torque, which means I wont be able to react to hazards. Running richer with dynojet stage 3, pods, yoshi exhaust, and aggressive throttle I still average ~45 mpg. Whats the point?

I understand the challenge of hypermiling and how it could be fun, but it seems like a waste of time on something that is already incredibly efficient even raced out. With fuel so cheap, you're literally saving a few dollars here or there, which will go back into your bike because hypermiling is likely much harder on the oil/gears/drivetrain. Especially if you're following the whole turn your bike off at a stoplight thing, which will absolutely destroy the already fickle starter in the gs500. Even worse if you've rejetted the bike to be extremely lean, because all newer GSes have garbage oil coolers that do almost nothing for the overheating problem.
[/quote]

[sledge]

So from a performance point of view, a 17/36t makes most sense.
The only problem I'm facing, is that with a 108 link chain, the rear sprocket will wear out the chain (or reverse). Sprocket/chain ratio couldn't be worse.
With the stock 110 link chain, the rear wheel chain adjustment will be close to the end, but it'll still be ok! Also chain-link/sprocket wear is quite good!

I can understand where you are coming from with this claim, its a take on the `hunting tooth` principle and you are absolutely correct

36 shares 7 factors with 108 and, only 1 with 110 so localised wear is (at least in theory) potentially going to be more of an issue with the 108 chain. However given the chain is subject to random shock loading, external contamination, varying manufacturing/material quality, possibly poor lubrication and alignment, is it going to be a significant issue  in the real world?......I think not.

http://everything2.com/title/hunting+tooth

As for some of your other comments and beliefs.......particularly `lugging`I will leave that to the others 

[MeeLee]

The venturi effect still is subject to a change in intake pressure.
If you spray oil on your air filter, you'll be running richer, because there is an increase in air resistance by the filter, so the otherwise perfect AF ratio will be compromised, less air means richer.

Likewise, if you manage to get the engine running at 90MPH at 5k RPM, there's less air resistance at the filter, for the same workload as a bike doing 9k rpm.

The lower RPM bike will have a slightly more opened throttle than the bike going at 9k RPM.

So the 'vacuum' effect still affects the AF ratio, as the fuel supply towards the venturi is at atmospheric bar, while the airflow in the carburetor is at a different pressure.

[MeeLee]

...
As for some of your other comments and beliefs.......particularly `lugging`I will leave that to the others 

I'm sure over time even those ideas will be understood

My English is not perfect, and my technical vocabulary is even less... But at least with trying to understand some people are getting what I'm saying..

[MeeLee]

I agree with two cool, especially his point about manifold pressure. Atmospheric pressure is due to the 100 mile high column of air that is trying to crush everything at 14.7 PSI. That's many tons of force on the surface of your body.

Where I disagree is running an engine at higher loads will cause premature wear. Maintaining a given speed takes only a small percentage of the power capacity of an engine but contributes greatly to efficiency in MPG.

The point where you are "lugging" an engine is when adding throttle imput does not result in increasing speed. My GS pulls fine from 30 MPH in 6th, with stock gearing, but not from 25 MPH.

If your goal is to maintain speed then use 6th for maintaining speed, down to 25 MPH, BUT if you need to accelerate, THEN you must choose the appropriate gear for the rate of acceleration desired sometimes from 6th down to even 2nd in extreme cases.

If you do not choose the right gear and try to accelerate in a higher gear, then prolonged operation under those circumstances will cause increased wear and tear.

I am a hypermiler, but not so extreme that it impedes the flow of traffic or aggravates other driver-riders unless they are agressive tailgaters or such, then I just get away from them as they are stupid and will cause an accident that injures or kills me and then they, the casue of the accident, will drive away leaving me to bleed out and die.

regards
mech

+1
I agree!

6th gear with a 17/35 goes fine down to 2750 RPM or 35MPH.
When the engine is hot, it goes down to 2500RPM or 30MPH, but I usually shift to 5th gear there!

[MeeLee]

...
BTW...Mr. Lee is so full of misconceptions, and lack of understanding..and ignorant of basic physics, that it would take a book to correct all of them!



Cookie

Be careful of what you're saying, or your words will be used against you when the time comes!
you don't know me,
You don't know what I know or what I don't
You presume I don't know something, and presumption is dangerous.
Especially when you flavor your words like that!

I may not know everything in the world, but I write my findings, and my beliefs, based on much more complex principles, findings, logic and math, than what I believe you fathom I do.

At first you where 100% against what I said,
Now that some people understand some of the things I say, you start backing off, but still continue your attack on the things that are not aligned with how you perceive things to be!

You presumed a lot by making the statement you did above!

What if I where a mechanical engineer? Would that make you tone down a bit?
Lucky for you I am not. I do this for fun.
And I'm open to correction, but the above I hardly see as a correction.
I see it merely as making fun of someone, just because you don't agree...

I have much more to say, but it's enough.
Discuss the venturi issue a bit further here, perhaps you'd be able to understand the principles.
I don't get everything, but I do notice things, analyze them, and give my closest possible answer to the problem at hand. My bike is running leaner at 5k than at 8k rpm.

[twocool]

Mr. Lee...

What I , (and some others) are trying to figure out is exactly what you are trying to accomplish....

So far all I can figure is you want the GS500 to go really fast and get really good gas mileage at he same time...

You also, for some strange reason, want the engine to run really slowly?

Can you elaborate on what you intentions are...what are you trying to accomplish?

As far as your engine running lean at certain RPM and not lean at others....on what do you base this claim?   Have you examined the spark plugs?  Do you have and exhaust gas temperature gauge?  Have you done even one "scientific" experiment?

Are you smarter than the engineers at Suzuki?


Cookie

...
BTW...Mr. Lee is so full of misconceptions, and lack of understanding..and ignorant of basic physics, that it would take a book to correct all of them!



Cookie

Be careful of what you're saying, or your words will be used against you when the time comes!
you don't know me,
You don't know what I know or what I don't
You presume I don't know something, and presumption is dangerous.
Especially when you flavor your words like that!

I may not know everything in the world, but I write my findings, and my beliefs, based on much more complex principles, findings, logic and math, than what I believe you fathom I do.

At first you where 100% against what I said,
Now that some people understand some of the things I say, you start backing off, but still continue your attack on the things that are not aligned with how you perceive things to be!

You presumed a lot by making the statement you did above!

What if I where a mechanical engineer? Would that make you tone down a bit?
Lucky for you I am not. I do this for fun.
And I'm open to correction, but the above I hardly see as a correction.
I see it merely as making fun of someone, just because you don't agree...

I have much more to say, but it's enough.
Discuss the venturi issue a bit further here, perhaps you'd be able to understand the principles.
I don't get everything, but I do notice things, analyze them, and give my closest possible answer to the problem at hand. My bike is running leaner at 5k than at 8k rpm.

[Dr.McNinja]

I don't get everything, but I do notice things, analyze them, and give my closest possible answer to the problem at hand. My bike is running leaner at 5k than at 8k rpm.

How are you sure? If you're positive this is happening I bet you're fuel starving your bike by hypermiling. The GSes are notorious for fuel starvation issues and are jetted really, really lean stock.

[twocool]

Mr. Lee...

I just re read your original post on this thread...and the many replies for those other than me...

I am not the only one poking fun at you....I am also not the only one who disagrees with your so-called "findings"

So I again state that you are a nut job!


Good Luck and have fun..


Cookie

[Atesz792]

[...]
Likewise, if you manage to get the engine running at 90MPH at 5k RPM, there's less air resistance at the filter, for the same workload as a bike doing 9k rpm.
The lower RPM bike will have a slightly more opened throttle than the bike going at 9k RPM.
So the 'vacuum' effect still affects the AF ratio, as the fuel supply towards the venturi is at atmospheric bar, while the airflow in the carburetor is at a different pressure.

OK, I've had enough of this. Filter resistance / pressure drop is relative, and it couldn't give a damn about RPM or anything else you're trying to 'explain' here.
Let me introduce you to the Hagen-Poiseuille law:
R =(L*η*8 )/(r^4*π) where R is resistance, L is the length of the 'tube' (we're modeling things simplified for now), 'η' stands for viscosity (law is originally for fluids), 'r' is for radius (that tube again...), and I really hope you're already familiar with π (pi).
Resistance of a given tube is dependent on these alone. In any system, this requires correction, since the cross-section is ~never a perfect circle, but RPM or velocity for that matter do not alter resistance.

Mr. Lee...

I just re read you original post on this thread...and the many replies for those other than me...

I am not the only one poking fun at you....I am also not the only one who disagrees with your so-called "findings"

So I again state that you are a nut job!


Good Luck and have fun..


Cookie

That's just too funny

[Old Mechanic]

I "hypermile" my car more than the bikes, but I just consider it efficient driving and riding (the jerk that named it "hypermiling" coined that term much later than my efforts began). My $650 (with 3300 miles) 04 GZ250 averages right at 80 MPG but not ridden like a "grandmother". If you want to blow past the speed limits, I'll do my best to not impede your effort shouldwe ever share a road.

Actaully the most efficient acceleration is at 80% of full throttle in feedback fuel injected cars (like the 23 year old Sentra), with full load enrichment, you want to avoid. My Sentra, bought for $300 has averaged 37 MPG for 6 months since purchase with best highway tanks over 41 MPG with 182,000+ miles. The wife drives a 2012 Sorento she bought new and paid cash for.

The GS 500 averages mid 60s, sounds about the same as yours, two cool, when ridden about the same way as you posted for the same mileage. The Sentra is currently rated at 33 highway and 28 combined, so I'm 40% over EPA combined, costing me about 5.6 cents a mile for fuel only. Insurance is $250 a year for me. The bike is 2.3 cents a mile.

I considered gas cheap when it was 18 cents a gallon, when my fuel cost was less than a penny a mile in a 59 Corvette that would do 140 in 3rd and get 21 MPG average per tank.

Bought an 84 CRX 1.5 brand new that averaged 44 MPg for 50k when a lot of cars would not do 1/3 of that MPG. Never got run over or squished by a jacked up truck with 0-60 in 10 seconds and I have driven mid 50s VWs with a lot less power than the CRX.

I learned in 1974 on a Kawasaki 900 what happens when you have a vehicle that is soo fast people don't realize where you CAN be. Got tired of cages merging into me even when they apologised and I realized from their perspective I should not be where I was. I learned to expect stupid and relish the times when I was wrong.

If I was that paranoid about gas mileage, my 1965 Honda 50 (super cub) does 170MPG, 128 MPG is one ounce per mile and it tops out at 43 MPH, tagged as a scooter, no insurance required, bought for $250, running the next day after 21 years sitting. It will barely climb my 12 foot in 80 grade climb to get to the top of my driveway, too steep for the 78 Schwinn Varsity I bought for $10.

I guess I could get better mileage driving slower, but with 30 traffic lights in a 20 mile drive, that typically takes me about 31minutes, if you go faster or slower you just catch more lights and take longer to get there.

If you think efficient driving or riding is foolish then consider this. A big honking 4x4 at 10 MPG, will use $20,000 at @ $2 a gallon, $30k at $3 in 100k miles. The Sentra would use a little over $5k in fuel (same100k). Having driven economically for the past 35 years and several hundred k miles, the money saved paid for my house, and my working wife paid the bills while I built all $310k of the house for half price.

regards
mech

[twocool]

That was interesting reading...well thought out...

I've always owned "economy" cars....(well I did have a beat up Ford F 250...but that was used only on rare occasions for trailing)


Hypermileing is an interesting concept....my dad did it before it had a name...50 years ago...

My concept is to buy a vehicle which is efficient in the first place (smaller car...scooter, motorcycle)...then enjoy the savings on fuel....but just drive "normally"...

My weekend commute is 320 miles.....My car gets 32 MPG (or better)..but the GS500 doubles that..costs 1/2....and is a lot more fun...win-win...

But it is easy to be fooled....motorcycles cost more to own and maintain than cars...and you still need to have a car too.....(Now double registration costs..increased insurance costs..etc)  ..so the actual savings of the motorcycle are quite small...compared to owning just a car...but it's fun....


I don't thing the GS500 really lends itself to hypermileing....I mean you can get 60+ something MPH without really trying....What is the full potential?   70 MPG?...probably not even that much over the course of riding in various conditions...As you said...in cars...improvements of 40% are realistic...but for GS500 I'd say you'd be hard pressed to improve gas mileage more that 5%....So I just ride the way I feel like riding...and am happy with 60+MPG...

Changing sprockets, chains, filters, plugs, exhaust isn't really going to amount to much...and you have to add in the cost of those modifications...It would be a long time before reaching the break even point..

BTW...when it comes to hypermileing...I think I've got all your vehicles beat!   On weekends I fly Gliders (Sailplanes)......I've flown over 400 miles on a single flight...I've flown over 8 hours on a single flight...and I've gone over 150 mph....and use NO gas at all...(since there is no engine)


Cookie



         

I "hypermile" my car more than the bikes, but I just consider it efficient driving and riding (the jerk that named it "hypermiling" coined that term much later than my efforts began). My $650 (with 3300 miles) 04 GZ250 averages right at 80 MPG but not ridden like a "grandmother". If you want to blow past the speed limits, I'll do my best to not impede your effort shouldwe ever share a road.

Actaully the most efficient acceleration is at 80% of full throttle in feedback fuel injected cars (like the 23 year old Sentra), with full load enrichment, you want to avoid. My Sentra, bought for $300 has averaged 37 MPG for 6 months since purchase with best highway tanks over 41 MPG with 182,000+ miles. The wife drives a 2012 Sorento she bought new and paid cash for.

The GS 500 averages mid 60s, sounds about the same as yours, two cool, when ridden about the same way as you posted for the same mileage. The Sentra is currently rated at 33 highway and 28 combined, so I'm 40% over EPA combined, costing me about 5.6 cents a mile for fuel only. Insurance is $250 a year for me. The bike is 2.3 cents a mile.

I considered gas cheap when it was 18 cents a gallon, when my fuel cost was less than a penny a mile in a 59 Corvette that would do 140 in 3rd and get 21 MPG average per tank.

Bought an 84 CRX 1.5 brand new that averaged 44 MPg for 50k when a lot of cars would not do 1/3 of that MPG. Never got run over or squished by a jacked up truck with 0-60 in 10 seconds and I have driven mid 50s VWs with a lot less power than the CRX.

I learned in 1974 on a Kawasaki 900 what happens when you have a vehicle that is soo fast people don't realize where you CAN be. Got tired of cages merging into me even when they apologised and I realized from their perspective I should not be where I was. I learned to expect stupid and relish the times when I was wrong.

If I was that paranoid about gas mileage, my 1965 Honda 50 (super cub) does 170MPG, 128 MPG is one ounce per mile and it tops out at 43 MPH, tagged as a scooter, no insurance required, bought for $250, running the next day after 21 years sitting. It will barely climb my 12 foot in 80 grade climb to get to the top of my driveway, too steep for the 78 Schwinn Varsity I bought for $10.

I guess I could get better mileage driving slower, but with 30 traffic lights in a 20 mile drive, that typically takes me about 31minutes, if you go faster or slower you just catch more lights and take longer to get there.

If you think efficient driving or riding is foolish then consider this. A big honking 4x4 at 10 MPG, will use $20,000 at @ $2 a gallon, $30k at $3 in 100k miles. The Sentra would use a little over $5k in fuel (same100k). Having driven economically for the past 35 years and several hundred k miles, the money saved paid for my house, and my working wife paid the bills while I built all $310k of the house for half price.

regards
mech

[Old Mechanic]

Thanks tc. A glider is one of the few things stil on my bucket list, would love to ride the updrafts and thermals on the windward side of the rockies.

regards
mech

[Janx101]

Hang on twocool! ... point of order! .. your glider doesn't use fuel but the tow plane or possibly the donkey engine on the ground cable does!? ... carbon footprint right there! Nyah Nyah!

[Dr.McNinja]

I "hypermile" my car more than the bikes, but I just consider it efficient driving and riding (the jerk that named it "hypermiling" coined that term much later than my efforts began). My $650 (with 3300 miles) 04 GZ250 averages right at 80 MPG but not ridden like a "grandmother". If you want to blow past the speed limits, I'll do my best to not impede your effort shouldwe ever share a road.

Actaully the most efficient acceleration is at 80% of full throttle in feedback fuel injected cars (like the 23 year old Sentra), with full load enrichment, you want to avoid. My Sentra, bought for $300 has averaged 37 MPG for 6 months since purchase with best highway tanks over 41 MPG with 182,000+ miles. The wife drives a 2012 Sorento she bought new and paid cash for.

The GS 500 averages mid 60s, sounds about the same as yours, two cool, when ridden about the same way as you posted for the same mileage. The Sentra is currently rated at 33 highway and 28 combined, so I'm 40% over EPA combined, costing me about 5.6 cents a mile for fuel only. Insurance is $250 a year for me. The bike is 2.3 cents a mile.

I considered gas cheap when it was 18 cents a gallon, when my fuel cost was less than a penny a mile in a 59 Corvette that would do 140 in 3rd and get 21 MPG average per tank.

Bought an 84 CRX 1.5 brand new that averaged 44 MPg for 50k when a lot of cars would not do 1/3 of that MPG. Never got run over or squished by a jacked up truck with 0-60 in 10 seconds and I have driven mid 50s VWs with a lot less power than the CRX.

I learned in 1974 on a Kawasaki 900 what happens when you have a vehicle that is soo fast people don't realize where you CAN be. Got tired of cages merging into me even when they apologised and I realized from their perspective I should not be where I was. I learned to expect stupid and relish the times when I was wrong.

If I was that paranoid about gas mileage, my 1965 Honda 50 (super cub) does 170MPG, 128 MPG is one ounce per mile and it tops out at 43 MPH, tagged as a scooter, no insurance required, bought for $250, running the next day after 21 years sitting. It will barely climb my 12 foot in 80 grade climb to get to the top of my driveway, too steep for the 78 Schwinn Varsity I bought for $10.

I guess I could get better mileage driving slower, but with 30 traffic lights in a 20 mile drive, that typically takes me about 31minutes, if you go faster or slower you just catch more lights and take longer to get there.

If you think efficient driving or riding is foolish then consider this. A big honking 4x4 at 10 MPG, will use $20,000 at @ $2 a gallon, $30k at $3 in 100k miles. The Sentra would use a little over $5k in fuel (same100k). Having driven economically for the past 35 years and several hundred k miles, the money saved paid for my house, and my working wife paid the bills while I built all $310k of the house for half price.

regards
mech

I see your point. I just am part of the school of that that says if you can't afford the gas, don't buy the vehicle. There's no point in detuning your supra/MR2/ferrari/whatever to get extra gas miles. Ruins the car and all the fun that comes with it. Same goes for literally any bike. Buy a geo/scooter if you want to save gas and have a weekend romper that gets 10mpg but runs a quarter mile in 10 seconds. I consider cars an investment in fun, and less as a way to get back and forth somewhere.

[twocool]

LOL...Yeah....I was waiting for that....but that's less than a gallon....(for a tow plane launch)...winch launch is ounces...(or electric)  ...it is possible and done many times to use human launching of a sailplane...they pull back on bungee cords....a couple places in the world, they just let' em roll down a steep hill and over the edge...

Then of course there are hang gliders...mostly foot launched..

Please don't tell me that you believe that carbon is a pollutant?


Cookie

Hang on twocool! ... point of order! .. your glider doesn't use fuel but the tow plane or possibly the donkey engine on the ground cable does!? ... carbon footprint right there! Nyah Nyah!