New Truck Help Which Oil?

Not open for further replies.
May 19, 2003
San Jose
I recently bought a 2003 Toyota 4runner V6 and it is coming up on the first oil change. I don’t know if I should use a synthetic oil or just oil ect. The manual recommends using 5w-30 oil. But a friend of mine said that if I use synthetic oil I would have problems with my seals in the long run. I live in San Jose Ca and thinking of using 10w-30 because it doesn’t get that cold out here. I will not go over 3500 or 5,000 miles on the oil changes.
Any suggestions?
My 02 Cavalier is getting frequent replacement of dino 5W-30 just like the owner's manual says. If anything, more frequently. Once the warranty is up, longer intervals with synthetic would be an option. In warmer weather, there shouldn't be much difference between 5W-30 and 10W-30. Keep Ford happy for now.
Your friend is wrong about synthetic oil causing problems with seals in the future. Synthetics are totaly compatable with engine seals. Just read a bit on this forum and it will be explained in detail to you. You will learn a lot of good info and the facts from the myths! If I were you switch to a synthetic now. I switched my 2003 Silverado to Mobil 1 at 2,700 miles. The experts will be here soon to help you out even more! Good luck!
Go with the 5-30 m1! Synthetics will be your best bet. I would change out the oil at whatever the manual says. I changed my breakin oil at 1500 miles and run 5-30 m1 in my 2003 tacoma prerunner. I will change the m1 at 5000 mile intervals. The toyota technicians also recommend m1.

The oil leak with synthetics is a myth, although if you already have oil leaks it will become more apparent with synth. You shouldn't have that problem with that "sweet" 4 runner.
I'd just go with the 10W-30 Mobil 1 (or amsoil). As was mentioned-seal leakage should be no more a problem than other oil. The M1 10W-30 has held up well. If you go with Amsoil-there is really no advantage with the 10W-30 you can go with the 5W or 0W. You can safely go with 6-7 K on Mobil 1. If you get hooked on this board you can start doing oil analysis and will probably find you can go up in the vcinity of 10K with M1.

Welcome to the board.
I have an '02 Tacoma V6. I switched to synthetic (Mobil 1) at 500 miles and now at 31k miles, it doesn't leak a drop. My previous vehicle went 240k on Mobil 1 and didn't leak. So much for synthetics causing leaks. In your mild climate, a 10w-30 would be a good choice.
When people talk about synthetic oil causing leaks, they are talking about when someone uses dino for awhile and the engine has alot of sludge and stuff that has sealed some of the leaks in the gaskets. Then they put synthetic in and it cleans all the sludge and stuff out of their and guess what: now you have some leaks!

hope that helps
also believe the leaks at seals was in fact a problem with some of the first synthetics more than 25 years ago. The oils were quickly reformulated to address the issue, but the myth persists to this day....
Not open for further replies.