Oil?

[Ingersoll]

I've used the 15W-40 heavy duty oils (aka truck oils, diesel oils) for my last 100k GS500 miles and don't think you can find a better oil for an air cooled motorcycle engine.  Used Rotells T, Delvac, and Delo brands but stick to the Rotella T now that they've tested and added the JASO MA motorcycle spec.

[black and silver twin]

I run full synthetic in both my car (5w30 royal purple) and bike (5w40 castrol rs4t racing synthetic) Both were broken in and run for thosands of miles on conventional, I switched to synthetic the day I bough both. Ive put 7000 miles on the bike with no ill effects after switching, and put 60000miles on the car since switching with no ill effects.

Synthetic oil is more durable and stable than conventional with NO bad effects. It wont cause a clutch to slip, energy conserving additives do that. it wont cause leaks, wear does that.

[jrains89]

Synthetic oil is the only way to go, using anything else is just asking for engine problems.

Wat?     I have a probe with 320,000 miles on it and has always used the cheapest oil. Runs great. While i'm not saying synthetic isn't probably better, it's just kind of ridiculous to say that conventional oil leads to engine problems.

[black and silver twin]

Synthetic oil is the only way to go, using anything else is just asking for engine problems.

Wat?     I have a probe with 320,000 miles on it and has always used the cheapest oil. Runs great. While i'm not saying synthetic isn't probably better, it's just kind of ridiculous to say that conventional oil leads to engine problems.

The MOST important thing with oil is to change it regularly and run the correct viscosity. running synthetic is just a bonus.

[burnymcstalls]

this discussion has been done once before, but the deciding factor between them is the oil's resistance to thermal and molecular breakdown ( through heat or shearing) and whether or not the oil contain friction modifiers to enhance lubrication on moving parts. With modern refinement techniques, the gap between them isn't as drastic as it once was, but you have a better chance of saving yourself from a boo boo ( like an overheat, or lack of oil) while running synthetic than conventional.

whatever you choose, make sure it does NOT contain friction modifiers for you bike, as the added ingredients wreak havoc on wet clutches, causing all kinds of potential wear and damage issues.

[mister]

+2 on the milk 

Before I started using 2% milk I used....

Came new from the dealer with Motul 1000.
1,000km service - Motul 1000
6,000km service - Motul 1000
12,000km service - Motul 5100
18,000km service - Motul 5100

Next time you're bored, why not ask about chain lube? 

Michael

[sledge]

this discussion has been done once before

Once??? 

[mister]

this discussion has been done once before

Once??? 

Well....

maybe twice...

BUT....

'twas a lo-o-o-o-ong time ago... right?

Michael

[Eklipse]

I used to use synthetic blend. Then my piston rod bearing went out at 11k miles. Could have had something to do with that wreck I got it.

Anyway, I use the cheapest oil in my 87 300zx (SuperTech, usually). 20w50 in the summer, 10w40 in the winter. 206k miles and still running strong. I change it about every 7k miles cause I'm poor. It burns about a couple quarts in between changes, but it's my baby.

Anyway, I spent all that extra money on synthetic blend after the break-in period and my piston rod bearing still went out and my crank is 4/2000ths out of round.

I really don't feel synthetic is worth the extra money unless you've got some exotic engine or you're running a race bike on the track.

If you're really paranoid about your investment and you have a lot of extra cash to blow for the synthetic, then go for it. I don't think it'll make much difference in the GS engine though, even in the long run.

Even if it saved having to change out a bearing or piston rings 10k miles earlier, the extra money you spent on synthetic would be more than the cost of the parts and service, and you would still have to do it regardless of whether you used dino or synthetic.

[Elijafir]

Here's my $0.04 (since I already gave my $0.02.)

I work at an oil shop, so i see a lot of used oil.  It doesn't matter what kind of oil you're using.. changing it at proper intervals to keep it clean is priority #1.  On bikes with wet clutches #2 is DO NOT USE OIL WITH FRICTION MODIFIERS.  I HIGHLY disagree with the thought that is okay to run Synthetic oil longer than conventional oil because "It's more resistant to heat and wear."  Synthetic oil is just conventional oil that they "re-arrange the molecules" to make it "more resistant to heat and wear." And IMO a waste of money.  Unless, like previously mentioned, you are using it in a high performance racing type setting.  The engines that use our conventional Havoline and actually come in every 3,000 miles or 3 months are ALWAYS more clean than the engines that use our Valvoline full synthetic and only come in every 7 or 8 thousand miles.  My Subaru (with less than 20k on a rebuilt engine and transmission) Was burning about a quart of Havoline every 3k mi.  It was burning about a quart of BG Full Synthetic every 3k mi.  It hasn't burnt off any Castrol, and it feels more smooth from idle all the way up the power band.  I know that the refineries are pretty much all the same in this modern time.. but, whether it is advertising and/or manifest reality because of my belief which is influenced by said advertising.. my car stopped burning oil and feels better with Castrol.  I'm sold and it will only be Castrol in all my vehicles from now on.  To me it's worth the extra few dollars for a "quality oil."  I do know different refineries use different filtration processes.  There is no other reason that a Valvoline oil can be so much more translucent than a super tech oil.  (Super tech looks like recycled used oil to me!)

P.S.  The WORST engine sludge we see is ALWAYS in cars that are using Pennzoil!!  (And I used to be a Pennzoil fan, until I worked where I work!!)  We have actually REFUSED customers because the Pennzoil sludges up their engine so badly!

[Norcon]

mobil 1 in the car
cheapest oil on sale for the bike.

I bought the car new, I do all the maintenance myself and decided that IF i was lazy and did a change late, it would be better for it to have synthetic in there. (I know Mobil 1 isnt PURE Synthetic, cue Amsoil salesman) After 30k miles, im considering changing to cheaper dinolube. I do all my changes on time (once in a while 300-400 miles late), I don't think its worth the extra cost, 10-15 vs 25-30.

As for the bike, the engine was designed before a marketed need for synthetic was developed, long as its clean and lubes, i dont care care too much.

[BaltimoreGS]

It doesn't matter what kind of oil you're using.. changing it at proper intervals to keep it clean is priority #1.  I HIGHLY disagree with the thought that is okay to run Synthetic oil longer than conventional oil because "It's more resistant to heat and wear." 

+1

In my decade as a mechanic I have seen customers who use every brand of oil known to man and every snake oil additive to go with it.  I have also seen plenty of ruined engines and the vast majority of them were caused by lack of maintenance.  Synthetic oil may be more resistant to heat, etc. but no oil prevents blow by.  The longer you leave the oil in your engine, the more blow by you have building up in your crank case.  The sooner you drain that crud out of there the better.  Most auto manufacturers recommend 5,000 mile service intervals now.  I still do 3,000 on my personal vehicles with inexpensive conventional oil.  Buy whatever oil makes you feel warm and fuzzy, changing it often is what will make your engine last.

-Jessie

[PachmanP]

dohabee I see what you're doin'

[dohabee]

dohabee I see what you're doin'

Who me? 

[vorBH]

I just put in full syntheic 10W-50 Belray...noticable difference!...way better, engine runs freely...better on the powerbands...feels less restricted

[tykho]

I can't believe how many replies this thread got, lol. The Valvoline motorcycle 10w40 was on sale for $3.50 a qt, so I'm happy!

[spc]

4/2000ths

Y'know, we're simple folk 'round here.  4/2000 is a little........ummm.....unsimple.  Maybe you could try 'simplifying' it to say 1/500th

[Eklipse]

lol fine, 1/500th out of round

I don't know how much of a problem that's going to cause once I get everything running right. I could hear knocking before, but the carbs were really lean.

[ohgood]

lol fine, 1/500th out of round

I don't know how much of a problem that's going to cause once I get everything running right. I could hear knocking before, but the carbs were really lean.

I'll assume you mean .010" out of round, which is -.005" / +.005", correct ?

Can't imagine a type of oil having anything to do with that happening. Maybe running it out of oil....