2001TransAm

I have a LS1 with about 30,000 miles, and use Castrol 10w30 oil. Should I be using sythetic motor oil instead? If so, what viscosity and brand?

skifast87

The oil caps states that the motor is to run 5W30. I do not believe that these motors even came new with synthetic. A great deal of people on this board do run synthetic however i just run castrol 5w30 run of the mill oil. The debate will never end as to what is better or what type of synthetic is better. Use the search bar and you can make your own decision.

WS6 Rampage

iTrader: (3)

0W-30 Castrol..... If you can find it!!

Try a search on this....theres a massive thread on this with a poll

blk97z28

iTrader: (3)

i am using Mobil one 5W30 and it run GREAT i have not had any problems.

JEB Garner

Amsoil 0W-30. I think that it is the best!!!

Jeresous

I'm running 5W30 Mobile 1 or Royal Purple, whichever is convenient at the time. The F-bodys did not come from the factory with synthetic but I do believe the C5s did.

Weezzer

Stick with what your using for now. Castrol 10W30 dino oil is one of the best without going to a really good synthetic such as Amsoil or GC. In my opinion what your now using is better than the Mobil 1 synthetic for the LSX cars. I tried Mobil 1 for three oil changes and my used oil analysis on this oil was so bad I dumped the third batch of Mobile 1 at 1600 miles just after I received the results from my second UOA of Mobil 1 . Go to bobistheoilguy.com and you can find many used oil analysis for LS1's covering all types of oil. Then make your own conclusions.
Now there are alot of people that are going to read this and go off because they love the Mobil 1. Thats fine, but what you will find is the vast majority of these folks have never done UOA to see what exactly is happening inside their engines. They go by how they "feel" when they change the oil or "we've used it for years and never....". Truth is until you analyise your own oil for your style of driving and your particular driving conditions vs type of engine - your not going to really know as in the end its just all speculation.

If I were you I'd stick with the Castrol and start doing used oil analysis at each oil change. Send your oil samples to blackstone labs and you will know exactly how your oil is protecting or not protecting your engine. They will send you free sample bottles to collect the oil.
This is the best advice I can give you, perhaps it will help.

SladeX

do an oil analysis with your current oil. If it's good, don't worry about it and just stick to it and change it at the recommended the lab will tell you.

Mobil 1 5w30 would disappear quick on me, 1qt = roughly 1000 miles. Had that low oil light popping on every week. I swapped to German Castrol 0w30 and I've gone 8000 miles with little oil loss. Used oil analysis told me everything was fairly decent with that oil.

jason1384

iTrader: (1)

Mine was factory filled with synthetic castrol but as an extra option.

Jeresous

I believe you about your oil analysis but I also wanted to point out there have been many independent studys done on Mobil 1 that yielded much better results.
Do a google search for "mobil 1 oil change life" .. the very first link is "synthetic oil life study" and goes into detail about the actual life of mobil 1 tested by many readers and is completely independent. I don't believe the study was ever fully concluded but it does give many great results and stats about the oil, many of them submitted by normal users.

intheclouds1977

I've done oil analysis on my '97 Chevy truck with dino oil and Mobile 1 full syn oil. The dino oil was good for 3k miles, the syn was good for 7k miles (due to engine particulates in both cases). There's obviously a difference in engine wear between the two. If you plan on running your engine to high miles, go for synthetic oil. You'll keep your compression and bearings longer.

Weezzer

Ok, let me respond to all your concerns here.
Remember this is my opinion based on what I've read and threads I've covered. This may or may not be fact. Its up to you to investigate. I haven't studied this info down enough to be an expert.
With that disclamer out let me start here:
The synthetic oil life study on Mobil 1 you refer to was done by PatMan in Canada. I believe he is still on this board, do a search and contact him, I believe he still upholds the opinion not to use Mobil 1 in the LSX engine. This study was supported by bobistheoilguy.com to which I referred you to in my first post. Since that time congress and the house of rep's passed a law that changed the formulation of oil that could be classified as synthetic.
The Mobil 1 formulation that Patman studied for 10,000 miles is NOT the formulation that you buy today. Its my understanding the PAO carrier base that is used to create the oil is now the #3 base which is made from petrolium distillates and is not a fully synthetic. The Mobil 1 formulation that was tested under the oil life study is now classified as the 15,000 mile tested oil that Mobil 1 passes off as its super improved oil at a super improved price (what a coincidence).
The new Mobil 1 you get today is of no relation to the blend that was tested in the oil life study (I belive the Amsoil results beat out Mobil 1 in this life study way back then).

Like I told the thread starter and I agree with SladeX - test what ya got and see what it gives ya.

But who knows? I could be off the wall here....
I belive it to be correct, but I do make mistakes.
I report - you decide.

HOMERDUDE4

I had excessive oil consumption on my SS M6. Chevy said will consume until the rings seat @ 30,000. They also told me to use Mobil 1 that will help. Well I do have considerablly less consumption and I was told 1 qt every 1000 miles is within Chevrolet spec. Anyone else????