What weight/type oil do you run?

[ChrisAU]

I've always ran 10W-40 dyno oil in all the 400's I've had, but I'm contemplating going to 20W-50. The only reason being that the truck isn't driven much, and the thicker oil should coat better before draining (is my thinking right on that?), and that my oil pressure is a little low for my liking after warm up haha.

I like to use Valvoline High Mileage btw. On my Tahoe it's Mobil 1 Full Synthetic 5W-30.

 

[Fobroader]

Amsoil full synthetic 5W-30 now, 10W-30 in the summer. Also, all of the fluids in the truck, Mustang and Jeep are Amsoil.

 

[Blue95]

20W-50 here, it leaks oil so this helps to slow it down, plus our summers are very hot here

 

[ChrisAU]

I think I'm going to stay with 10W-40 Valvoline Maxlife, but this time w/ a quart of Marvel Mystery Oil. I've read that it is very good at cleaning an old motor. Also going to use a Mobil 1 Filter this time as I found the oil filter test thread on here.

 

[ChrisAU]

What about 15W-40? Hmmmm

 

[big_mike]

Castrol GTX 10W-30 in the truck & in my TA both & I only run the Purolator filters. I have ran Castrol in my TA for 7yrs now & over 100k miles. When we opened it up for the head swap it still had the original cross hatchings in the bores with 101k miles on the clock. Been running another 70k miles since then without a single oil issue.

 

[withoutfear33]

i run mobil one 10w 30 in mine but a buddy runs 20w 50 in his and says his ran better with it, he started running 20w 50 in it because it smoked a lil and was buring a little oil but now hes saying it actually runs better with it.. im not much on oil so is there any reasoning behind this? will this harm a motor? seems a lil heavy to me for the winter months when it gets down below freezing.. but then again i dont know muc about oil.

 

[big_mike]

You do have to watch oil weight in different climates. Too thick or too thin isn't good.

I have seen some cars/trucks notice this as well. Sometimes its just the factory bearing tolerances are a little looser & the thicker oil just works better. Sometimes its b/c the bearings are old & worn.

 

[withoutfear33]

You do have to watch oil weight in different climates. Too thick or too thin isn't good.

I have seen some cars/trucks notice this as well. Sometimes its just the factory bearing tolerances are a little looser & the thicker oil just works better. Sometimes its b/c the bearings are old & worn.

yeah i told him i thought he should at least run somthing a little lighter in the winter months but he doesnt listen.. it gets down around 10* here usually in the winter and hes still running 20w50 lol

 

[Blue95]

I think I'm going to stay with 10W-40 Valvoline Maxlife, but this time w/ a quart of Marvel Mystery Oil. I've read that it is very good at cleaning an old motor. Also going to use a Mobil 1 Filter this time as I found the oil filter test thread on here.

I would only run that stuff one time, I run lucas somtetimes, but now it doesn't stop my oil leak and 20w-50 doesn't really either
I also wouldn't waste my money on a mobil 1 filter, I would run a Wix or Purolator before a mobil

What about 15W-40? Hmmmm

I have run that before, Shell Rotella T is probably the best oil out there.