I guess Im gonna try the Castrol 5W40.

This sounds like a kind of dumb question, but is there a way to visually tell the difference between Synthetic and Conventional when draining? Ive tried searching for it, tried asking people...

 

I think there are subtle differences in the color of clean oils but as far as used I have no idea. I presume you want to see what the previous owner has been using? Probably have to use an UOA.

 

Thats what I figured... I highly doubt Synthetic has been ran in it though. Thanks.

Right as I was going to hit the submit button I remember there is a sticker in the windsheild for a oil change that was done a little before I bought the car at a GM dealership local to the area. I gotta see if it lists any more information.

 

Is their goal absolute longevity or best ET? Those things may or maynot go together. We certainly can learn from race cars but just because they do something doesn't mean it is right for us.

I know Ferarri used some 10w-60 stuff that is like $65 a quart that must be the best so we all need to use that right?

On the 0w-30 M1 I have not seen any UOAs on it in awhile so I don't know specifically about that one, formulas constantly change so the ONLY way to know what works is to keep up on UOA results which is what that link Physic posted a few pages ago will allow you to do.

As I have said before I find it mind boggling that the same folks who demand dyno charts and time slips to PROVE a mods worth will blindly dismiss the one tool we have to actually measure an oils performance, the UOA those are where I point you. I have no blind brand loyaly to try to justify and frankly at this time am not using any of the oils being discussed. Being winter and warmups causing fuel dilution so I can't stretch out the interval the daily driver wagon got Maxlife 5w-30 as it is a step between synthetic and dino and below zero temps are a reality here.
Don't remeber what is in the Caprice as when I dumped it in I knew it would only see maybe 1500 miles before the topend was torn down., so it was something inexpensive.

 

Well, it does have room as it is the same engine bay etc as the 91 Vette which was a L98, but had conventional oil. There are sublte differences, but the elimination of the oil cooler made Mobil one necessary.

 

Ive been searching, GTX is only sold as 5w40 here, Im not sure if the 40 weight is too much, or maybe its a good thing. But I saw that they sell GM Long Life 10w30 here also, anyone have any experience with it?

 

I was half joking but there are tight clearences in there. I would probably pull my hair out if I had a Y body.

 

I'm no oil guru but the 40 is probably gonna have higher temperature properties which your car will probably never need/use. However it being a 5w, you're gonna get a broad range of temperature protection and I venture to say it would be fine. As far as the GM oil, I wasn't aware that GM had an oil. Is it contracted to someone? What does the bottle say on it?

 

Yeah I dont think the summer is going to be as hot for as long as it is in Florida, so thats why I was uncertain about the 40 weight, and the car is stored for the winter (Novemeber - April).

As for GM Long Life, I cant find any more information for it (nor have I ever heard of it before), I just saw it listed (no pictures however) at the automotive store site... Guess Ill have to look into it when Im there.

 

Look at it this way, if you couldn't use that oil in your area, then they probably wouldn't sell it there.

 

Yeah, but there are only a handful of these cars here... so Conventional oil here is intended for tractors and such. When I looked more into it, the 5w40 Castrol GTX even turns out to be a Synthetic (one that is locally available). I spoke with a guy on the F-Body Club of Finland, he said that I will have to look for non-approved "Castrol dealers" to find a regular GTX...

I gotta ask what my friend (who owns a US-car/part store) recommends, hopefully he has a filter for me and some oil (which is brought from the US because he imports and sells only US cars and trucks here).

 

castrol is not a real synthetic anyways. Last time I checked Mobil 1 and other synthetics are group 4s while the castrol is a group 3...

 

...In North America. I think in Europe however it's gonna be a G IV due different laws and such. At least that's what I have gathered in my scrolling of the VW forum.

 

^^ Prolly true then I'd have to go do some reading for myself

 

castrol syntec 5w-30 switching to mobil 1 read a lot of good reviews so time to test it

 

I use the big daddy brand green is in 5w30 and 20w50 in the Malibu!! we have gone three on our race motors and bearing still look like new.

 

3 years I hate to type lol

 

I got a 94 t/a 25th anniversary (its my first lt1), i have a 01 ls1 for the past 5 years and running M1 5W-30 with no probs, and the car has 45K. Did 25th t/a's come with synthetic from factory? The car has 110K miles on it. I need to do a oil change, any suggestions? Car has no oil leaks at least that I can see.

any feedback would be most appreciated.