Thinner oil in 454?

[Jeff1961]

I have a 1995 7.4 3500 GM pick up. I am running M1 5/30 now. I tow a 8500# toy hauler about 1000 to 2000 miles a year. The rest of the time, it's short trips to work. I recently rebuilt with a high volume oil pump & tow cam. At start up it has over 80 psi oil pressure. It never runs less than 50 psi at highway speeds at it's hottest, up mountains ect. I would like to change to 0/20 M1 for better flow at start up & MPG. The 10 psi per 1000 rpm rule is met, is that all that matters? (The red line starts at 4000 rpm.)
Any reason I shouldn't go to a 0/20 M1 or..?

TNX

 

[DrDusty86]

Go to a 0w-30 M1.

 

[A_Harman]

The main reason that I can think of is that GM recommends 5w30 for that engine. How about trying 0w30 M1? If you're towing in hot weather, I say stay away from the 20 weight. Maybe you can use 0w20 in the winter when the oil temperature won't get as high.

 

[kcfx4]

i wouldnt use xw20 in that engine if engine is used to tow haul
or ran hard, just my opinion

 

[Astro14]

I would go 0W30 M1 - you're looking for better flow at start-up...that will do it.

I seriously doubt that a slight decrease in viscosity will make any appreciable mileage difference in a 14,000 GCWR rig...

I wouldn't go below a 30 weight - that's what the engine was designed to run on, so bearing clearances, etc. are sized for 30...your pressure is good with a 30 in there - so why risk the change?

 

[bullwinkle]

German Castrol Syntec 0W30!

 

[Jeff1961]

Thanks,

Was definetly going to at least a 0/30.
I have only recently been educated on the 0/ oils.

 

[tig1]

Even though M1 5-30 will be excellant for your engine, 0-30 should give you excellant results as well.

 

[cchase]

I would definitely NOT run a 20-weight in a BBC engine. Or a SBC for that matter. These engines would prefer a 40-weight over a 20-weight.

 

[TallPaul]

I run Maxlife 10w30 in my motorhome with a 454V8. I also boost the zddp in it to SL levels (1000-1200 ppm).

 

[dave1251]

You could use a 20WT oil and you would not see a much of change in your PSI. But you would not see much improvement in your MPG.

 

[PontiacFan]

Originally Posted By: Jeff1961
The rest of the time, it's short trips to work.


Thinner

 

[901Memphis]

Maxlife synthetic 5w30

 

[bryceban]

Originally Posted By: cchase
I would definitely NOT run a 20-weight in a BBC engine. Or a SBC for that matter. These engines would prefer a 40-weight over a 20-weight.


This

 

[Blaze]

How about M1 Truck and SUV 5w-30? That still has to flow pretty good at start up.

 

[electrolover]

your not going to get much better start up than a syn Xw30
i would not go to a 20w

 

[daman]

As we speak I'm running 5w20 in and old school 350 Chevy thats in my plow truck, engine has great oil pressure. If the truck isn't being used to tow heavy loads or experiencing high oil temps? yea it'd run 5w20 in that mill you have plenty of OP to support bearing loads.

 

[dave1251]

Originally Posted By: daman
As we speak I'm running 5w20 in and old school 350 Chevy thats in my plow truck, engine has great oil pressure. If the truck isn't being used to tow heavy loads or experiencing high oil temps? yea it'd run 5w20 in that mill you have plenty of OP to support bearing loads.


The idea that a 20WT motor oil could provide oil pressure that is in PSI specs just does not compute with some people.

 

[daman]

Originally Posted By: dave1251
Originally Posted By: daman
As we speak I'm running 5w20 in and old school 350 Chevy thats in my plow truck, engine has great oil pressure. If the truck isn't being used to tow heavy loads or experiencing high oil temps? yea it'd run 5w20 in that mill you have plenty of OP to support bearing loads.


The idea that a 20WT motor oil could provide oil pressure that is in PSI specs just does not compute with some people.

Been running it all winter here plowing, bearings are still there.

since he has above average OP there should not be a problem.

 

[dave1251]

Originally Posted By: electrolover
your not going to get much better start up than a syn Xw30
i would not go to a 20w

You will not let this go will you? Don't you understand if you achieve the correct PSI with 20WT motor oil this does not cause wear. Using a lighter weight oil actually reduces wear due to faster start-up, reaching operating temps faster, and better heat dissipation.