SAE 40 or 20W-50 Valvoline racing oil?

Which one for my 360 which will only see street use and not be driven in cold weather?

Any differences or is it pretty much a tossup?

I prefer this brand oil due to it's higher levels of ZDDP.

TIA

Royal Purple 10W-40

You can get the VR-1 in a 10-40 and other weights also. I just bought a case for my Dakota. Napa had to order it in. They got it overnight. Cost around $45.

If your engine was built with close tolerances,why would you want to use such a thick oil? Especially on an engine that will mainly see low R.P.M.'s.

Don't run the heavy goop.

run the 20-50 or order something like 10-40 like was said.

Run the lightest weight oil you can for best flow at start-up; I've been running 10W-30 for decades, even in the racecar and never a problem. the heavier the oil viscosity, the more power and fuel you'll use pumping it. I'm assuming your bearing clearances & oil pressure are normal.

VR1 10w30

When I owned Mopars in the 70's , I always used a 20w-50 oil. Back then it was Kendall GT-1 ( now Brad Penn). I now use Valvoline Racing 20w-50 for the same reasons you cited.

That's what my engine builder said, and NAPA is the place to get it.
Jim

I recommend the 20-50.. everyone has a personal choice, but if you ever get stuck in traffic or your engine simply runs hot the 10w stuff turns to water and cannot protect like a heavy vis. oil.
Any extreme activity like high RPM or heavy loading or a short period with no oil, like start up or starvation, requires the most protection you can get, not the least you can get by with..

I would recommend 15/40 or 10/40 most applications unless you are running with a lot of bearing clearance you don't need any heavier oil.

I would NOT use anything that has the numbers 40 or 50 in a tsreet engine.

Any so called engine builder still building street motors with clearances so loose you HAVE to run thick oil is not an engine builder IMO but an engine butcher.

FWIW I just used the 20w-50 VR-1 in my 440....I was running Rotella 15w-40 in it since it was rebuilt about 6k miles ago....
Switched because of the better Zinc levels in this stuff

20w 50 VR1 user here.

The 10W-30 VR1 is only three viscosity points lighter than the SAE 40 VR1 @ 212 degrees (F), which is considered to be normal operating oil temp.

At 100 degrees (F), the SAE 40 VR1 is 59.8 viscosity points thicker than 10W-30 VR1.

The better flow of the 10W-30 VR1 at cold engine start-up (even at 100 degrees (F) will protect your engine better considering both oil viscosities at operating temp are so close.

In a street car, your motor oil operating temp (not to be misconstrued with coolant temp) will hardly ever see 212 degrees (F).

20W-50

Quote:

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If your engine was built with close tolerances,why would you want to use such a thick oil? Especially on an engine that will mainly see low R.P.M.'s.

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Even factory tollerences should only require 10w 30 or 10w40.

20w 50 is too thick in a fresh motor

As for straight weight's(sae 40, etc..) they are for lawn mowers, given the availability of much better modern stuff.