I just bought a '00 ws6 with 70k on it, I have no idea on the previous oil that was used in it, would it be wise to use mobil 1 in it? I have heard so many conflicting things about switching over with a higher milage motor.

 

most people with their ls1 run mobil 1 5w 30. i don't think that it should be a problem with a higher milage motor. i run ams oil and like it a lot better than mobil one. its all preference. but you should be fine with you motor.

 

Mobil 1 5w30 (and 10w30) is too thin for a hard driven LS1. If you must go with Mobil 1, use their 5w40.

There are better oils out there than Mobil 1 though. I prefer German Castrol 0w30, but other good choices are Castrol 5w40, Amsoil 5w40 or Royal Purple racing 41.

 

ok thanks, what about the stuff i've heard like you'll get oil leaks you've never seen before and crap

 

Quicksilver, the oil leak thing started around two decades ago. Seals and manufacturing have come a long way since then. I'm not saying it CAN'T happen, only that it isn't nearly as likely as it may have been in the past. I've never seen it, and I don't know anybody personally that has. Try synthetic, and if you find any problems either try a heavier weight oil or go back to petroleum stock.

I hear a lot of discussion about what weight oil to use. The owner's manual suggests 5w-30 for cooler weather and 10w-30 for warmer. It isn't going to kill anything if you use either of those weights unless you beat your motor to within in inch of its life.

German Castrol? Whatever. Analysis numbers I've found/seen show and either/or conclusion to me. Some of the numbers were better for Mobil, some for Castrol. Is it enough of a difference to sell the wife and kids to buy? Not in my opinion. Much is said on this forum about decoding manufacturing codes and how hard it is to find. If I was standing at the oil aisle and it was jumping up and down waving its hands, I might buy it. Some say it's a thicker oil for its weight class. Ok, but so what? Get a slightly heavier Mobil oil and what's the difference?

You can't go wrong with any brand name synthetic motor oil of a reasonable weight. You just can't. They all work. But fit the tool to the job. If you thrash your motor, get a heavier weight oil.

$.02

 

I've been running mobile 1 5w30, no problems, no leaks

 

I changed my oil 3 times with 110k miles, my car is still dry and runs fine... idk what they are talking about.

BTW- I use mobile one synthetic 10w 30 now

 

The thing I heard about switching oils in a high mileage engine was that if you switch from regular to synthetic, you might start getting oil leaks. One theory was that regular oil leaves little carbon deposits inside the engine, and synthetic would remove those deposits, revealing little holes underneath that would then leak. Another was that synthetic oil's smaller molecular composition would make the engine start leaking where it didn't leak regular oil before.

After a bunch of reading on http://www.bobistheoilguy.com (great site), a friend and I decided that those theories were probably crap and switched our high mileage cars (NOT LS1s) over to Mobil 1 from regular oil... thousands of miles later, no leaks.

I don't know what oils are good for an LS1... I still haven't made my own decision on what to run in mine that I bought a few months ago. But from my short time reading this board, Patman seems to really know his stuff, so I'd be confident that what he says will work.

 

yeah just dont forget when you changin the oil and the oil filter, finger a light coat of oil on the seal or it'll be a bitch to take of later. just a reminder, I know of alot of my friends forgetting to dab alil oil on the seal and cussing it out when it was time to change oils.