It's that time again. Right now I have Mobile 1 Synthetic 5w-30 in it at about a little over 3k miles. I'm considering a switch but i don't really know a whole lot about oil.

The car has 93,645 Miles on it and is running STRONG. I don't really go to the track cuz its far away, but i do get on it from time to time, so i want something that's not going to suck under pressure.

I just recently installed some headers, so I have been driving it a little harder than usual. I live in California near the desert, so it gets pretty friggin hot here, around 105 some days. However i have a 160 thermo with manual fans so it never really goes over 190-200 on those 105 degree days.

I want an oil that can put up with the intense heat, and still lube my engine with ease. Any recomendations?

 

Mobil 1 5W-30. You already use the best oil you can get. Stick with it.

 

Mobil 1 5w30 is too thin for the LT1. If he's going to stick with M1, then 0w40 is the better choice.

I have been getting awesome oil analysis results using 0w30 Castrol Syntec (the German made version) in my car. This 0w30 is almost a 0w40 though. Mobil 1 5w30 is almost a 5w20.

 

I'm sure the suggestion to run Mobil 1 5w30 stems from the fact that GM decided to recommend that weight. After all, it's right there on the oil-fill cap right.

Original poster states that he doesn't know much about oil. In that case here's a link that might help you understand more about it.

http://www.bobistheoilguy.com/

Happy reading.

-Mindgame

 

You should really change to 10w30. In ares where the temp gets 100+ and winters normally dont get less than 30 is where you would use 10w30. 5w30 is for colder areas where the temp gets possibly a little under freezing at times, but not normally over 95. Read your manual thats where it tells you either 5w30, or 10w30.

 

Maybe you should phone GM and tell them all this. And also the American Petroleum Institute, and the Society of Automotive Enginneers. Between those three modern engine oils are about the most highly tested and regulated products we put in our cars.
Just how you came up with your theories I don't know, but compared to what API and SAE say, I also don't care.
By the way 5W-30 and 10W-30 have the same viscosity at 210 F. which is why they are both "30". One is thinner at the lower test temperature of -18F. That's it. Check with SAE if you don't believe me.

 

Alright, what?

So should i stick with Mobile 1 5w-30 or move to the 10w-30... Summer's comin up quick guys...

 

Go to the link given by Mindgame and read and learn my friend.....Patman's info is based on facts(oil analysis) not theory.

Use the Mobil 1 0w40....a "better" choice IMO also, based on analysis Ive seen.

 

Well you see, the problem is that i honestly just don't understand what the hell they're talking about. Viscosity at so-in-so temperature under this amount of whatever...

I just want to know if my engine is going to blow up if i stay with 5w-30 or if i should move to a different oil based on the given conditions in post 1.

Thanks.

 

No your engine will be fine with M1 5w30.

 

Vader, oil analysis results don't lie. It's the truth, LT1 engines like an oil which is a thick 30wt to low 40wt oil. So they like an oil which has a viscosity at 100c of somewhere between 12cst and 14cst. Mobil 1 is only 10cst, and as a result, you'll see higher lead content in your oil analysis when using it in an LT1, meaning you're getting higher bearing wear.

GM might be recommending Mobil 1 5w30 for use in the LT1 Corvettes, but it's more to do with marketing and the "factory fill contract" that Mobil 1 secured with GM, than anything else.

I should clarify that I'm not saying that you can't get long engine life with Mobil 1 5w30, just that you can get a longer engine life with other choices.

 

Oils of the same weight rating do vary peiod and all oils are not equal and they often do not stay the same weight over useage.
5w30 was a CAFE thing not a best for the motor thing, one look at the owners manual will show you that 10w30 is acceptable. Now Ford and Honda are specing 5w20, everything I have seen is they did not tighten up bearing clearances when making the switch, well the motor didn't change so I wonder what could cause the new spec, CAFE . Argueing oil with Patman is like agueing hostess cakes with Rosanne you aint going to win. He is a moderator on that oil site.

BTW I am running Rotella T synthetic 5w40, not in the normal isle at Walmart, check the desiel section , should be doing an analysis soon.

 

I have a 102k mile LT1 and using Valvoline 10w-30. IMO, after 100k miles, time to move up to 10w-30. 5w-30 is fine for a new engine. I always run valvoline.

 

i use mobile 1 supersyn 10w-30.

 

You misunderstand me Patman. I am not arguing with you, you are arguing with the API, SAE, GMC, and to some extent ILSAC.
Last I heard, the Mobil 1 requirement for Corvette, and Porsche, and myriad others was to get through the warranty period, and the CAFE rating was met by selling tiny cars to offset the sport-utes.
I am aware that the 0W-40 European spec oil is a fine viscosity. I may try it myself. But if GM says 5W-30, and warranties their engines for that oil, that's good enough for me.
It is important to remember that the API and SAE specs are set forth by the manufacturers, and the oil companies develop oils to suit them. Some manufacturers don't like to recognize industry wide standards, like Mack, who continues to spec their oils to their standard, and expects oil companies to produce them or they will void the engine warranty. Mack is at rating "EO-M" I believe. Cat and Cummins also did this, but at the urging of API most are now agreeing to a single API C-H4 standard.