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What Viscosity Oil do you use?

What viscosity oil do you use?


  • Total voters
    60
What viscosity oil do you use in your truck?
 

F 150Cobra

"Wild HoRsE" Got Torque?
3,642
104
Aruba
in my old truck i used to use 40 HD or 50 HD

in my new engine im gonna use 10-30
 
Last edited:

91xltlariat

Pennsylvania Chapter Member
74
4
10w40 in summer, 10w30 in winter.
 

LEB Ben

Arrogant A-hole At-Large
34,919
1,124
outside your house
I use several...after a fresh rebuild 15w40 Rotella. After about 15000 miles, MotorCraft 10w40, and when the oil is blowing outta the tail pipes or starts leaking...20w50.
 
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john112deere

caffeine junkie
Staff member
10,807
405
central Vermont
10W-30

That's what the guy I got it from used for 200k miles. One day I happened to read that the Ford spec for that engine is 5W-30...tried it the next change, and drained it out after about 30 miles. My lifters didn't like it, and complained audibly.
 

LEB Ben

Arrogant A-hole At-Large
34,919
1,124
outside your house
The first oil change I did on the Bronco, all we had on the shelf was some 10w30 for my bro's jeep...well I used it, just to get some fresh oil in there. Well...I'm pretty sure it was so thin that the engine didn't even bother to blow smoke out the pipes...it just blew straight fluid...haha. Obviously an exagerration...but you get the point.
 

UNRULEE

^LARGE carbon footprint^
I use 5-40 Rotella Syn in the PSD.

For the '79 it's Rotella 15/40 in the summer and Rotella 10/30 once it gets cold.
 
I use Castrol GTX 20W50 in the truck because it never gets that cold here and the thicker oil lubricates better IMHO. Probably why it still had hone marks in the cylinders at 145,000 miles... practically zero wear. :)
 

Skandocious

Post Whores Make Me Sick
19,076
655
California
I use Castrol GTX 20W50 in the truck because it never gets that cold here and the thicker oil lubricates better IMHO. Probably why it still had hone marks in the cylinders at 145,000 miles... practically zero wear. :)
It also adds stress to the engine if the heavier oil is not needed... Thing about eating peanut butter and trying to smack your tongue against the roof of your mouth, versus doing the same with water. You gotta work harder to overcome the higher viscosity of the peanut butter.

A crude analogy-- maybe. But similar principles apply.
 

CowboyBilly9Mile

Charter Member
7,118
442
USA
I use Castrol GTX 20W50 in the truck because it never gets that cold here and the thicker oil lubricates better IMHO. Probably why it still had hone marks in the cylinders at 145,000 miles... practically zero wear. :)

Where were the hone marks at? Top or bottom of the bore and were they on the sides of the cylinder closest to the wrist pin or the sides closest to the piston skirts?
 

CowboyBilly9Mile

Charter Member
7,118
442
USA
Where were the hone marks at? Top or bottom of the bore and were they on the sides of the cylinder closest to the wrist pin or the sides closest to the piston skirts?


Bump.

Conner, you were on 45 minutes ago this evening :) ..................
 

Beachbumcook

Kansas Chapter member
Hey... you guys left out us diesel truck owners in the poll!!!

There was no option for 15W-40 or 5W-40 rated oils!!!

So... I choose "other".

Don't upset the band of diesel merry men... we are a mean bunch of beer drinking drunks!!!!
'peace' smilieeatndrink 'peace' smilieeatndrink
 

mrxlh

Oilfield Trash
5,904
430
Stigler, OK
15W40 so voted other.
 

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