just bought 2002 sc 430 not sure if has had synthetic oil or not. Is it ok to start with synthetic now with 95000 miles or use something else?

 

yes you can use synthetic even if it hasn't ever been used in it. The statements about it causing leaks and such is a myth nowadays. Back in the 70's and early 80's yes it could because of how the additives worked with the gaskets. Since then the additives hydrates the seals and gaskets just as well as Dino oil.

 

Either synthetic or conventional is fine. You can go 7500m with syn and 5000m with conventional.

 

Synthetic, switched over many moons ago. Conventional oil is beginning to disappear from the shelves. Cost wise, relative to mileage per change is almost equal. So take the synthetic option.

 

Service manager at the local Lexus dealer showed me their service manuals entry stating conventional oil is used on sc430 which I used today

 

I know, service advisor at the Lexus dealership in NC says the same thing. I have stuck with conventional but I think I am about to switch to synthetic for the longer change interval. I think the Lexus position is more related to legal issues than science. The advisor that I asked a couple years ago says they put in what came from the factory.

 

Lots of 300-400k mile sc430's reported using conventional oil. Would seem the engine was designed for it

 

I switched to synthetic at 80,000 miles. Then I noticed a puff of blue smoke when starting cold that had never been there before. I ran it for 1500 miles, but decided to switch back to dino. The smoke stopped as suddenly as it had started. I'm sticking with dino.

 

we all have our opinions but changing the oil on a regular interval will help ensure many trouble free miles!
if you beat the crap out of it every time you drive, all bets are off.

 

I've been using Pennzoil synthetic on my GS400 since 2007....right when it turned 100,000 miles. I do like the longer change intervals. The SC is due for it's first oil change pretty soon (since we purchased it) and I will probably go with synthetic for it as well. It's not driven much so that means probably one oil change per year (less than 5,000 miles).

 

I build a specific brand and model of Austrian single cylinder dirt bike four stroke engines and at least on these 2000-2007 model year motors the full synthetic makes these specific top end components last longer.

That being said these engines were made with a combo of a nikasil plated aluminum cylinder and a low expansion alloy piston and a cast iron top compression single ring.

medium ring life. Less expensive to make for a volume manufacturer.

i switched to a special alloy steel liner and a normal steel ringed piston.

triple the ring life

using a conventional oil helps the ring seal instead of a full synthetic in these motors.

had a customer draw abrasives through an engine due to poor air filter mounting and at 150 hours the bike started smoking.

had him remove the full synthetic oil and go back to conventional oil which is nominally 50% Dino oil and 50% synthetic.

smoking stoppped within 2-3 hours of use as the rings reseated themselves.

just an observation plus the hundreds of owners feedback on the net regarding engine life and issues using different oils.

100% perfect results from everyone using "conventional" oil. Which is part synthetic already.

no reason I can find to spend more money on full synthetic oil when not apparently needed and may be hurting the ring seal?

puff of smoke on a seasoned engine that goes away when back to part Dino oil was an interesting piece of info.

thanks.

Bob