High Mileage Oil

[brucelee]

I am about to do an oil change on my new (to me) 95 sc400 with 104K miles on it. I am thinking of using Mobile 1 10-30 or 15-50W. I have a tad of blue smoke upon starting the car up first thing in the morning but the car runs fine and passed CA smog with no problems.

My thought is that running a heavier oil is appropriate with a higher mileage car and that the synthetic oil will be easier on the car when starting up.

I have always used Mobil 1 and am a big fan so the issue is strictly which weight oil to use.

I appeciate your input.

[99lsguy]

I think your logic is good!

I'd start with the 15w-50 . Since its the first (possibly) use of synthetic oil for the car I would change the filter after 500 miles or so and then change oil AGAIN at 1500 miles cause the synthetic should break a lot of gunk loose.

Maybe just change will conventional oil first and then run 500 miles - then change to the SYNTHETIC.

I started using 5-30w full Synthetic at 53k (nowwith 59K) miles and no problems.

Do you have any reason to believe the seals (valve gaskets, pan gasket, etc) are leaking?

If they are clean, then I don't see why you couldn't use the 10-30 either... ;)

[sightdev]

Depend on oil consumption, and little lost of oil is ok and it is normal. Try the 5w-30 per manufacture recommendation to give better flow and gas mileage. Last change I added Restore per someone’s recommendation and I can feel and hear the difference. SC400 is a hot running car because it lacks good air flow to the engine compartment so IMO Mobile One is the best oil. I change the oil every 7k mile with synthetics on all my cars present and past and I never had engine failure (except for the Mustang 5.0) in the past 23 years of driving.

[SPORTcoupe300]

I used to do 7K changes until I blew an engine in a Camaro. (I suspect it's from using FRAM oil filters)

Now I do 4K changes with Synthetic and Toyota filters in my SC.

It's bit more expensive but I bet it will same me money in th elong run.

[Lextech2k3]

ok here is the lexus tech answer.....i have personally done an oil change on more than one 200K mi+ car using 5w-30 oil...my father owns a 96 ls400 that has 190k on it right now and it too smokes for about 10 seconds first thing in the morning...this is 100% normal. what has happend is that the valve seals are seaping a little from wear over the years...this condition will not cause problems..it's just a simple hicup that engine has after a while...don't worry about it just use a good 5w-30 or 10w-30 oil and use a lexus filter..believe me i've seen for myself that there is in fact a difference...(make sure that the filter has plastic on the sealing side or else it's a fram knock off that the dealer is using to try to save money).

[brucelee]

That is great stuff and I thank you for this. Do you see any issues with using Mobil One 0-40 oil? I happen to have 6 qts in the garage and dont want to waste it?

Also, being a tech and all, is there some easy way to tell if the timing belt has ever been changed on my car. I assume that at 104K, this issue should be addressed if it has not already been changed.

Thanks a lot.