VGLNTE1

Not the brand as the "what's better" will take over...I use 15w50 and in This weather I hate it take 5-7 seconds to get pressure in this cold...thinking of running a 0w40

dvandentop

15w50 as well

wallyman424

Used to run the M1 5w30, then I was educated on some oil things and am now running the fancy valvoline non street legal 15w50. Its chocked full of extra zinc.

Hopefully I havent ruined a good thing by switching.

Bills Z06

15W-50 for me.

Gary(SF)

I use 5w-40 Total Quartz (Elf product). Excellent writeups from the guys that do oil analysis.

-Gary

L98Terror

15w-50 M1, but I use the Valvoline in my C4

bosco022

5w-30 Mobil 1 in a road race LS1 stock car.

Good oil pressure, low oil temp this past weekend at Sebring

VGLNTE1

so...whats the point of running a 15w? if that is the W at cold, why wouldnt we all want 0-5W to move through the motor faster on start up?

VGLNTE1

how is oil non street legal? why why the zinc?

wallyman424

I believe its because of the additives, like the zinc are in such high quantity that the government does not like it (emissions I suppose).

Zinc (aka zddp) is absolutely crucial for preventing engine wear. M1 5w30 used to have zddp, but the new formulation doesnt have any.

Sidney004

It is the phosphorus component of ZDDP that poisons the catalytic converters. A race oil might have 2500 PPM of ZDDP, 4X-5X the level of a SM rated oil. Even modest levels of blowby past the rings will degrade the cats. ZDDP excels in providing boundry layer lubrication; when your oil film degrades due to high g's or loss of oil pressure.

Sidney004

The new formulation has ZDDP, just less of it; they have other anti wear additives as well.

Glennm27

15W-50 track, 5W-30 Street,

VGLNTE1

is it a synthetic or a dino oil?

whats the name of it?

wallyman424

Actually I'm running 20w50... its synthetic.

http://www.jegs.com/i/Valvoline+Raci...VV855/10002/-1

redtopz

Amsoil 0W30 synthetic mixed with Amsoil 10W30 racing oil. The racing oil has high zddp for engine protection, but no detergents so you have to change you oil frequently. That's why I mix 50/50 with regular synthetic for the best of both worlds. BTW, you can get a preferred customer discount with Amsoil and they will ship everything directly to your house including filters etc.

VGLNTE1

so back to my question...why run a heavy cold weight?

4wheels

For serious track cars xxW-40 or xxW-50 oils makes sense. The 50's are pretty darn thick, and honestly I don't think you need to run one unless you've either rebuilt the engine with loose tolerances or are seeing 300F.

Also just because one oil claims it's a 0W-40 and another a 5W-40, doesn't guarantee that the 0W-40 is ANY thinner when cold.

I run a 5W-40 HD oil made from group 4 & 5 base stocks with a strong additive anti-wear additive pkg, and decent detergent pkg. Thin enough to where I get oil pressure instantly & have good pressure when hot at the track.

Another option if you run thicker oils is an oil tank heater.

VGLNTE1

My car sees mostly street use...hard use, but the street. think I better switch to a 0w-40.

I was running 15-50 because my 416 LS3 would get to 240* with just driving around in the summer. 260-270 with romping on it. This was after I installed the splitter and before the oil cooler.

LEAVINU

I see same as coolant temps just cruising around in my H/C LS2 with Royal Purple 5W-30.