First Gens and Synthetic Oils

[george0fthejungle]

Hey everyone and especially First Gen Guru's,

 

Has anyone had any experience using synthetic oils in older bikes? I ask because last year I switched to Mobiles synthetic 10k oil in my cars and saw a noticeably cooling operating temperature and a slight increase in MPG.

 

This got me thinking about trying it in my '83 Venture but Im hesitant to leap before asking around. I dont put more than 5 - 7k miles a year on the bike so its not reducing how often I change the oil that appeals to me, rather Im interested in running the bike a little cooler and hopefully squeezing a few more miles out of each tank.

 

Any opinions?

 

GeorgeoftheJungle

[Venturous Randy]

I ran Amsoil motorcycle synthetic for a while and it did fine except for the leaks I did not have before.

RandyA

[george0fthejungle]

So you saw some leaks...and then I take it they stopped when you switched back to conventional oil? Thats definitely a consideration.

[dynodon]

There should be no additional leaks. Many people have heard about synthetics leaking and thus when they change, they look for them. quite often, the leaks were there, or just start for no reason other than it was time.

 

Why does synthetic have a rep for leaks? Because when synthetics first came out, they were among the very first oils to have detergents in them. At the time cars had leather and real rubber seals that leaked anyway, but the oils of the time had a lot of parafin in them and the accumulated dirt from no detergent led to some leaks being blocked by the gunk inside the engines. You start using any detergent oil, and the leaks that were plugged by the gunk start leaking. They would leak with any detergent oil, but synthetics got the rep.

 

Also, people feel synthetics are "thinner" than regular oil, and that leads to people looking for and expecting leaks. In reality, when cold, synthetics flow better than regular oil that turns to thick sludge in cold weather. This gives better starting, less wear. Once oil gets hot synthetics are THICKER than regular oil because they retain their viscosity better. Thus they leak less when under pressure, but no oil, not even that with huge amounts of STP in it, will stop leaks under pressure.

 

I have many examples of people switching to synthetic and their oil use goes DOWN. In my own case, my '89 SHO (this was in 1993) used a quart of 10-30 regular oil every 2500 or so miles. Switched to Amsoil 0-30 and oil use (from leaks or burning) went DOWN to about a quart in 4000 miles. Why? Less friction, Synthetics won't evaporate as quick as regular oil, and it keeps it viscosity better when hot, leading to less oil getting past the rings/seals internally.

 

Most oil use is from burning the oil, usually through valve guides and also rings. Synthetic helps with this.

 

I am sure the leaks RandyA mentions happened, but I doubt seriously if Synthetic was the cause.

[george0fthejungle]

Thanks for you input Don. Its funny, Im texting the mechanic I take my bike to. He brought up the leak thing and also said he didnt think it was good for a wet clutch.

 

Im specifically considering amsoil brand because I guy I work with runs it in both his cars and his bike (a Buell). He showed me the dipstick on his car thats had the stuff in it for 11 months, 12 yr old Honda Civic and the oil was still honey colored and almost no dirt particles visible. He said it runs them cooler and he gets better mileage.

 

Im still undecided but I appreciate the input from members, whether its pro synthetics or against!

[starkruzen]

I have always ran Mobile one for 4-stroke motocycles in my bikes. No problems at all!

[SilvrT]

When I had my '87 which had over 100,000 kms I tried synthetic and the clutch started slipping under load in 4th (a bit) and 5th (quite a bit). I've read where others have experienced similar and the rule of thumb seems to be that if it's used to non-synthetic and has quite a few miles, don't change to synthetic.