Originally Posted by Railrust
Originally Posted by billt460
I switched to Mobil 1 10W-40 High Mileage in my 1991 F-150 5.0 V-8. I did it because I have a rear main that's leaking. And from people I talked to here, they said it might help cut down the leak by reconditioning the seals. (Something high mileage motor oils are supposed to do). I switched to synthetic because I thought it might be a bit "better" at it.
So far no improvement in just over 1,000 miles. I'm also told the longer you use it, the better chance it has to work. So we'll see what happens in time.
I did the same type of stuff when my Lexus LS 460 started using oil. Car was fine up until around 140,000 miles, never used a drop. Then around 140k it started to use a little...then at 150k a little more. By the time I had reached 178,000 miles it was using a quart every 1,200 miles or so...tried heavier weights, nothing helped. I ended up trading it in, it needed other repairs and it was time, but I probably could have driven that thing another 100,000 miles without issue, just adding the oil.
Mine doesn't leak enough to have to add between changes. So if this stuff cuts down on it or not, I'll just keep driving it the way it is. I park it over a couple of those big metal drip pans, so it's not a problem.