Fuel economuy

[shchuka]

Ok, so my case probably isn't too typical.

I use my GS almost entirely for commuting and putting about 320 miles per week on it.  Of my 65-68 miles commute about half is on an open road with 70mph speed limit, where I do about 85-90 usually, and the other half is through the city centre in rush hour traffic with a lot of stop-start-stop-start... you get the idea.

I get an average of about 51-52 MPG on all this commute (I check at the fuel pump - check how much I put into the tank, check how many miles I rode since last fill-up, reset trip-meter).  I know this is about average, so I shouldn't really complain.

I got the bike about 3,000 miles ago - about 2.5 months back.  Oil changed, carbs cleaned, plugs replaced, clutch adjusted (I know, not important here), front fairing installed, drive chain tension adjusted.

What else can I do to get better MPG?  I'm in UK, so petrol (gas) is quite expensive comparing to the States.  These days, it costs me about £27 (about $40) per week in fuel - so I'm looking where I can save a quid.

[ojstinson]

Here is your problem;

"I do about 85-90 usually, and the other half is through the city centre in rush hour traffic with a lot of stop-start-stop-start".

I'd say you're lucky you average 51--52 MPG, that's excellent milage for that kind of riding.

[shchuka]

Well, there's nothing I can do about the rush hour city centre.
I can, I suppose, ride on the motorway at 70, but then I'll be the slowest vehicle on the road   What's the fun in that?

[zukertort]

Well, there's nothing I can do about the rush hour city centre.
I can, I suppose, ride on the motorway at 70, but then I'll be the slowest vehicle on the road   What's the fun in that?

Fun and fuel economy do not belong in the same discussion. I know, my wife has a Prius.

[dgyver]

Since you are not going to slow down to burn less gas, change you sprocket gearing to lower your rpm at highway speeds. Either go up a tooth in front or down a couple in the rear. This will affect accelleration though... but what is the fun in that...

[jp]

Running those speeds on the highway, you're not going to significantly improve your mileage. Last year I averaged 50.6 mpg over 7100 miles with a commute similar to yours. This year I'm averaging 53.5 over 5800 miles so far. The biggest difference is a friend visiting for several days who rides much slower than I normally do. My mileage for those days was up to 60 mpg. I have been improving my gas mileage a bit by shifting between 4500-5000 rpm instead of my usual 6500-7000 (which is much more fun). Changing your sprockets and short-shifting may gain you a couple mpg, but it takes a lot of restraint to maintain that riding style if you're used to revving the engine. I expect my overall mileage to be within 1-2 mpg of what I had last year by the time I call it quits on commuting this year.

[shchuka]

Well, basically, as I expected.  Don't get me wrong, 51-52 isn't bad (it's not 70 I was getting with my old 125cc yamaha, but GS is a lot more fun to ride).

I changed the front sprocket just a couple of weeks ago. It's now welded to the shaft due to a diferent problem - so no more changing front sprocket on this baby (at least without changing the engine along with it).  I was thinking about going a tooth less, but decided against it due to a lot of high speed riding.  I don't normally rev the engine too much and upshift at around 5.5K.  I'll try doing 75-80 instead of 85-90 for a week and see what effect it will have.

[black and silver twin]

installing a taller rear tire would make the final gearing effectively taller, which would give better mileage.