Mobil1 0W40: suitable for crate 460?

[JCoop]

I currently have 10W40 Mobil1 in it. No leaks whatsoever at 5200 miles, and have read excellent write-ups on the "euro blend" 0W40. I've had excellent performance with 0W40 in small block 351W SPF, and a 302 crate motor in the CAV GT40. I'm getting ready to finally hook up an Accusump that's sitting on the rail but not plumbed, so I'm thinking of using the 8 qts of 0W40 I have in the garage, with the cooler weather and very little useage over the winter...any thoughts?

[Bob In Ct]

Mobil1 does not come in 10W-40.

The 0W-40 is actually heavier at lower temperatures than is the 5W-30. It's also heavier at high temps, which you would expect. I use the 5W-30 Mobil1 year round with lots of pressure even in the heat.

It's all on their site at www.mobil1.com

Bob

[JCoop]

Originally Posted by Bob In Ct

Mobil1 does not come in 10W-40.

The 0W-40 is actually heavier at lower temperatures than is the 5W-30. It's also heavier at high temps, which you would expect. I use the 5W-30 Mobil1 year round with lots of pressure even in the heat.

It's all on their site at www.mobil1.com

Bob

Sorry, I meant 5W40 truck/diesel synthetic. A bit hard to keep track, I do ALL oil changes in 6 vehicles. I put it in when I got the car in March, 1600 miles ago.

I don't understand how 0W40 can be heavier (thicker) in lower temps than 5W30. Doesn't the first number indicate viscosity at a given low temp?

[Bob In Ct]

I don't get it either, but the viscosity numbers are from Mobil's web site.

www.mobil1.com

Bob