Gear Ratio and Tire Size

[HSKR R/T]

I don't have any need for oversize tires, but tow over 5,000 lbs on a regular basis. I still accelerate faster than the idiots always blocking my way on freeway entrances. When nobody is in the way, I can still hit 80 on the ramp while towing. The only reason I can see for a 3.92, besides towing over 8,00 lbs is wasting gas.

I get batter gas mileage than some people with 3.21s claim, and that's with a lift and bigger tires.

 

[6of36]

I get batter gas mileage than some people with 3.21s claim, and that's with a lift and bigger tires.

It's not due to the bigger gear. Some trucks will just get better than others, optioned the exact same. Physics tells you that the driveshaft has to turn 20% more to travel the same distance. Unless the transmissions have different final drive ratios, a 3.92 will use more gas.

 

[HSKR R/T]

It's not due to the bigger gear. Some trucks will just get better than others, optioned the exact same. Physics tells you that the driveshaft has to turn 20% more to travel the same distance. Unless the transmissions have different final drive ratios, a 3.92 will use more gas.

Too many variables to make that absolute claim.

 

[Dewey]

Guess this just turned into yet again another gas mileage thread.

 

[Mountain Whiskey]

Guess this just turned into yet again another gas mileage thread.

How many do you think we are up to now? They seem to be endless don't they?

 

[Scram1500]

What's a 3.21?

 

[Hadit55]

What's a 3.21?

You stop it!

 

[JF19Longhorn]

I'm sure you will feel it and your mpg will probably take a hit.

I have the 3.92s and went to the Mickey Thompson Baja Boss ATs LT275/60/R20. I'm down 1 - 1.5 mpg and I notice it takes alittle bit more to accelerate, especially at hwy speeds. My truck never, and I mean never, dropped out of 8th gear when going hwy speeds.. even going over bridges with a decent grade or those spots in the PA turnpike with the extra lane for semis cause the grade is pretty 'steep'. Now, she'll drop to 7th with a slight incline in an attempt to maintain hwy speeds (65-70mph).

 

[6of36]

What's a 3.21?

The right ratio if you don't need to tow over 7,000 lbs.

 

[HSKR R/T]

The right ratio if you don't need to tow over 7,000 lbs.

The right ratio if that's what you wanted.

 

[Mountain Whiskey]

What's a 3.21?

The right ratio to haul a loaf of bread home from the grocery store. If you skip buying the bottled water. Or going uphill. Or if you don't mind the Prius honking at you as he is passing.

 

[Hadit55]

The right ratio to haul a loaf of bread home from the grocery store. If you skip buying the bottled water. Or going uphill. Or if you don't mind the Prius honking at you as he is passing.

Wow I didn't realize the 3.21 was that bad. I think im gunna trade mine in for one with a numerically unlimited gear ratio

 

[Mountain Whiskey]

Wow I didn't realize the 3.21 was that bad. I think im gunna trade mine in for one with a numerically unlimited gear ratio

Now you're thinking with coal! Git that thing moving!