K-Spaz

My car is a 98 with the original motor. I am nearing time for an oil change. In the threads I've read here, I've never seen anyone mention running conventional oil in one of these LS motors. Is that a no-no? If so, for what good reasons, remembering I'm out of warranty long ago.

Zorlac

Tons and tons of threads on this. I have always used M1 per GM. Next time I may try the Pennzoil Ultra or Mega or whatever it's called these days. Some folks said it made their motor more quiet. Either way it will be synthetic.

NukeC5

I think as long as you run fully synthetic you are fine. Beware of oils that say synthetic blend. (Like Casterol etc.) they are not fully synthetic. Mobil1, Royal purple, and Valvoline make the best fully synthetics out there IMO.

lucky131969

Here we go again........

K-Spaz

Any insights as to why they call for it? Something mechanically important? I know VW has been calling for Castrol GTX fully synthetic in their engines for a while, and in fact they say you void the warranty if you even change brands. Probably more of a bribe/kickback thing than anything mechanically sound. I've never cared for Mobil 1 in any of my cars, just never seemed to 'feel' right. I've run it, didn't seem to have adverse effects. But, I would certainly not remain brand loyal to them from past experience. If anything, I'd probably use Castrol (as cautioned against above). But, truth be told, I'd really rather stick to conventional oil in the car. I'm guessing that fuel economy is the main reason GM goes to this stuff, and if that is the only bonus, it's not enough to keep me.

K-Spaz

Well, doing a search on oil yielded a page full of threads, not one of which asked about conventional oil.

sunchaser73

with lucky
Look up the GM spec and use one from the list...

lucky131969

Pssssssst.......I have a secret to tell you, but you can't share it with anyone else......shhhhhh

Your car is not under warranty anymore, so use whatever oil you want. What type you use, and how often you will have to change it, will be dictated by how you drive your car(daily, auto-x, etc), and if it is synethtic or conventional.

Enjoy...

C5Natie

100% Many good oils out there. Personally I like 15w40 Rotella T in my cammed cars....and thats a conventional oil, and its FOR DIESELS. Lol. Im sure the Corvette police is looking for me.

strand rider

I've read the use of synthetic oils allowed a more sophisticated engine design, as it was tough to cool some projected designs before the superior lubrication. The Ls series of engines was only put into production after the new oil solved a few heat issues.

Always use the best oil you can. Yes, there are probably guys out there using crap oil that think they know better ,and that the engineers and car company are just trying to trick him with their fancy oil specifications. Good luck with that.

Once I saw that top fuel racers were reporting they had eliminated oil failure as a cause of parts failure when they switched to synthetic , I switched and never looked back.

Well, I did check. My new at the time 1994 Ford explorer, burned a little oil between changes when new. I wasn't that happy with that fact. Now over 130,000 miles and oil consumption is unchanged from new, a result not possible with the old random molecule oils. Now the same oil consumption rate that I used to consider marginal is superior to mosts cars of that age, because of the oil.

If you want to ignore the specified correct lubricants, how far wrong do you want to go? Conventional oil, kerosene , suntan lotion , water , will all lubricate your engine, but on an inferior level than the oil specified for the job. Some might even let the engine run long enough so that you might think you had made a good decision and saved some money.

Take care of your machines and they will take care of you. Try to run them outside of the designed limits and then you need to be ready when the machine responds outside of its intended function . As in, car no work.....metal shavings inside oil hole.......need fix....money.....need money.....need call cab.......

egrand333

Synthetic oil was not recommended for the Ls1 engines in the 1998-2002 Camaros.

cdkcorvette7

Let me help you out: http://lmgtfy.com/?q=site%3Aforums.c...nventional+oil

This has been discussed many times before; the search above will give you tons of threads to read on the subject. Some members run dino oil, I don't run dino in any car anymore. There's just not that much of a difference in cost to get a superior product.

strand rider

I guess I should have been more specific. I was reading information about corvette engines and was repeating information from that reading .

The info they were publishing was only about corvettes.

YELLO C5

Amsoil. Use to run Royal Purple at the track and had pressure problems at 292F. Switching to Amsoil seemed to improve that a bit.

Bill Curlee

With the very close tolerances that the LS engine uses and the high heat that the engine runs, it will be tough running a conventional oil without changing it a LOT..

I’ve had NUMEROUS high mileage C5’s apart and I have YET to see ANY of the sludge deposits that you commonly see in engine using conventional oil. I have 60,000 miles on my 02 ZO6 and I can still see the honing marks in the cylinder walls.

Like Lucky stated,, run what you want, if it makes you feel like you making an improvement. Those GM Power Train Engineers are IDIOTS anyway..

If you think you’re going to save a few bucks,, think about changing the oil every 3K-4K miles vs. 12K-15K.
BC

K-Spaz

My questions weren't really geared toward cost. It was more from personal experience with engines that just didn't like the synthetics because of the really low viscosity. Things like lifters bleeding down as I see some people here have complained of. Leaks . I've had cars with lots of valvetrain noise using too low a viscosity oil. Yea, they were not built in the synthetic days, but this thing is a 98, and well, I'm new to LS motors. I don't think the 6.0 in my 03 Silverado counts. It does have fully synthetic oil in it however. It's my only vehicle that does.

I don't know how accurate the gauge in the car is, but it shows a hot idle oil pressure of around 30psi. Pretty much never above 40 when cruising. I figure that's partly because it takes the oil pressure at the top of the block and is showing what the valvetrain is getting, not what the crank gets. But I'm not sure that's right. If that's all the crank is getting, then I might be concerned.

I guess it's all trial and error. I guess I just have this mental problem with really low viscosity oils.

mikede824

baxsom

the sad part is the people that run the GM spec oil and still change it every 3K miles. That is the real waste of money. Might as well light a 20 on every ever 4 months.

Mobil1 is not the GM required oil but it is the GM fill (marketing) The owners manual requires a specific GM spec which is now Dexos1. Look up the list of Dexos 1 approved oils and you cant go wrong. The reason supposedly the Corvette LS1 and the Camaro LS1 have different oil specs is the operating temp of each.

Vettmann17

I love these oil threads.

oh1vette

and up from the ground came a bubblin crude...