An Engineer's Ultimate Guide To 3.21 VS 3.92 Axle Ratio

[Ramroo]

It's impossible to be any more correct than this.

Yes, you should have bought a Prius.

 

[SnowBlaZR2]

Yes, you should have bought a Prius.

Would buy one before I settled for a truck with 3.21s.

 

[Ramroo]

Would buy one before I settled for a truck with 3.21s.

Just poking ya a little.
I had the heart shot…. had to take it.
We all need to go goog fishin and MW bring the jugs.

 

[SnowBlaZR2]

Tell you what, towing on I-70W and these side roads through the Rockies, I'm glad I have the 3.92s.

 

[TNRamGuy]

They fish by the light of the moonshine down there too! (It's just not as good as VA shine)

Couldn't agree more, I am partial to tidewater damson berry myself, but a Clark/Fredrick tart cherry can get-r-done also.

 

[Mountain Whiskey]

if it’s even possible to get this thread back on the rails…which is better with 35 inch tires? assuming the 5.7

Rails are right under the tires. The truck runs great with 3.92s and 35s. Lower gears are a must with bigger tires. This is especially true if you go with heavier mud treads.

Tell you what, towing on I-70W and these side roads through the Rockies, I'm glad I have the 3.92s.

I'm jealous. I have never been through the young mountain range in the west. Just the worn old Appalachian range here. I'd love to head out there and see a Dark Sky park when it's clear.

If you brought some eastern shine with you there might be some good goog fishing on those side road campsites!

 

[SnowBlaZR2]

Rails are right under the tires. The truck runs great with 3.92s and 35s. Lower gears are a must with bigger tires. This is especially true if you go with heavier mud treads.



I'm jealous. I have never been through the young mountain range in the west. Just the worn old Appalachian range here. I'd love to head out there and see a Dark Sky park when it's clear.

If you brought some eastern shine with you there might be some good goog fishing on those side road campsites!

If I had 3.21s, probably would've had to stop in Denver.

 

[theblet]

If I had 3.21s, probably would've had to stop in Denver.

View attachment 136487

What did you hide in that manhole?

 

[SnowBlaZR2]

What did you hide in that manhole?

There's a truck with 3.21s in there. We tried, but the trip up was too much for him and he didn’t make it.

 

[theblet]

There's a truck with 3.21s in there. We tried, but the trip up was too much for him and he didn’t make it.

I figured it was an extra can of gas for you to get down from that hill without running out.

 

[SnowBlaZR2]

I figured it was an extra can of gas for you to get down from that hill without running out.

Truck's computer can't even calculate how high my MPG is.

 

[NHRoadking]

Got my 2022 with 3.21.

Plenty of power and great gas mileage. I drove the same truck the the 3.92. It was a bit quicker off the line but busier on the the highway. My F150 had a 3.55, a nice compromise.

It's nice to have choices.

 

[Mountain Whiskey]

A GG woke the sleeping giant thread!

 

[WXman]

There's still no way in hell I'd ever buy another truck with 3.21s, but I do at least feel a little better about this axle ratio after I was able to take my cousin to the wood shed in a roll race (in Mexico) last week. His truck is a 2020 F-250 Supercrew FX4 with the Powerstroke. 1,050 lb/ft of torque from the factory, 10 speed trans, and 3.73 axle I'm pretty sure. Gave him a one truck length handicap and we both hit the throttle at about 35 MPH and I ended up putting a school bus length on him. Honestly we were both surprised

 

[theblet]

A GG woke the sleeping giant thread!

And we’re back!

 

[Eighty]

A GG woke the sleeping giant thread!

Lol! Man, do you have some kind of alert set up that notifies you if a member types 3.92 and 3.21 in the same post?

 

[User_3336]

A GG woke the sleeping giant thread!

Only 5 months. i've seen 2 year old threads resurrected! LOL

 

[theblet]

Only 5 months. i've seen 2 year old threads resurrected! LOL

should I get a cold air intake? Somebody help!

 

[deeve]

What kind of oil do you recommend for the 3.92? Is it different than for the 3.21's? I think I remember reading something about using boutique oil will help compensate for getting the wrong gearing.

 

[Dewey]

should I get a cold air intake? Somebody help!

Yes….of course. My butt dyno shows at least 50 hp. Compensates for not having 3.92’s.