Oil Weight Q?

[MOPARJ]

I live in mild SoCal weather and run 20w50 Valvoline VR1 racing oil in my 6500 mile 318 .030 over rebuild, Comp cam 4 bbl in my Duster. It runs great that way with great oil pressure and has not used a drop of oil in 1700 miles since my last oil change.

I am keen on oil weights and chemistry, but was just after opinion here. Is this too heavy and will cause damage over the long run, or is it ok to use, even though it is a bit heavier in weight. I am not worried about the slight power loss of a heavier weighted oil. With this oil, it is noce not to have to run an additive, since it has plenty of zinc.

 

[68 Sedan]

A 20/50 to heavy?

Not hardly. I used to run straight Penn 50W in my big blocks in the summer, and switch to the "lighter" 40W in the winter

never any problems

 

[340butterduster]

I'm a "Royal Purple" 20W50 user, and have been for many years. I will agree with the weight maybe robbing (a minimal) amount of power, till the engines gets to operating temp. But i've had no issues, nor do I forsee any related to the weight.

As mentioned before, as long as you don't have below freezing temps. and cold starting the engine, it will be fine. In fact I personally believe it's better, if you are going to drive it a bit hard.

Giles

 

[Petzschler]

20w50 is a tad much for a 318.. unless the motor is REALLY worn out.
15w40 would be a very good compromise oil to use (if its available in Valvoline Racing Oil).

 

[moper]

It wont hurt anything. But it does give up a little power to a lighter bretheren. Being that you are running better oil, and changing it regularly, and the egnien has been rebuilt, you can probably run 10 wt with no issues. You can also run a lighter straight weight instead of a multi viscosity.

 

[dustertogo]

It appears that we're basically talking about a street car here so I think the issue about a slight power loss with the heavier oil is being overplayed quite a bit. Unless you're "dyno racing" or actually racing at the strip where you're concerned about every tenth, then I think anyone would be hard pressed to actually feel this difference "seat of the pants".

 

[ramcharger]

The big question is how much clearance your rod and main bearings have been set up for. If you are running over stock clearances, 20W-50 is a good choice for warm weather driving. If you are running stock clearances or tight stock clearances, 10W-40 is fine and gets the oil up top and on the cam quicker on cold starts but 20W-50 offers more protection above 90F.

 

[moper]

While I agree for some people feeling the difference might be difficult, I dont agree it's overplayed. It's all proven fact. Heavier oil and high volume pumps are simply overkill for 80% of engines with them, and that usage simply uses horsepower (in the order of tens at peak, not 1 or two) by turning it into heat that goes directly back into the oil. If there is doubt, look at the modern engine and the 0W and 5W oils spec'd, or look at synthetics that show dyno numbers at the tire of 8-9hp and lower engine/oil temps. Some people can't feel a difference in a K&N or a fram open element. It doesnt mean it isnt doing the same job better. It's just someone take advantage of it.