3.31 vs 3.73 Highway MPG Difference

[JCsTruck]

First and second gear with the ten speed are so low that the transmission must shift real early with the 3.73 gears when driving normally. I have the 3.31 gears and to me my supercab feels quick.

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[NavyChief]

I use the dash as I’m too lazy to hand calculate but I’ve had a pretty good spread of 5 liters.

22 XLT RCSB FX4 3.31s ~18mpg with whipple (25k miles)
23 XL RCSB 4x4 3.31s ~19mpg (work truck 12k miles)
21 Lariat Supercab SB 4x4 3.31s ~19mpg (15k miles)
21 XLT RCSB FX4 3.73s ~19.5mpg with whipple (20k miles)

Mine are pretty consistent and honestly I didn‘t really notice that much in mileage but I will say the 3.73s are by far better seat of the pants with responsiveness. It just feels so much lighter/better. I had the last 2 at the same time (traded the Lariat for a superduty) and it was a very noticeable difference (talking pre whipple) between the trucks. I would jump in the Lariat and it just felt more numb to input.

 

[TacoJon]

I am getting re-geared today. Was kind of interested in doing this for a while. Truck is at the shop. Yes, it was a pretty penny but I had the pennies. I will post back after I get the truck back. Luckily there was a Ford dealer here in Denver willing to do it and not void my powertrain warranty.

 

[JCsTruck]

I am getting re-geared today. Was kind of interested in doing this for a while. Truck is at the shop. Yes, it was a pretty penny but I had the pennies. I will post back after I get the truck back. Luckily there was a Ford dealer here in Denver willing to do it and not void my powertrain warranty.

I was wondering if you did any instrumented testing before so you can do an after. That would really be useful and make things truly comparable.

 

[NavyChief]

Not sure why but I don’t have any noticeable difference in any metric but it just felt better. You will love the new gears. Did you go 3.73?

 

[TacoJon]

Not sure why but I don’t have any noticeable difference in any metric but it just felt better. You will love the new gears. Did you go 3.73?

Yep - 3.73. Might eventually level and get a slightly bigger tire. Nothing crazy though.

 

[TacoJon]

Got my truck back. Running and driving well. Definitely more pull at low RPM but I am trying to take it easy for the first hundred miles while the gears settle in. Can't really hop in the highway yet either.

As soon as I got my truck back we got hit with negative degree temps and the roads are semi-permafrost now so I can't really drive like how I would want until some of the ice melts and temps go up. Will report back once it warms up a bit and I can get some interstate time with the new gears.

 

[JCsTruck]

Nice!

 

[JExpedition07]

With a 4.69:1 1st gear ratio it doesn’t matter much. Acceleration will be identical in the 1/4 mile as 3.73 lose leverage at high speed requiring higher rpm per wheel rotation. The 3.31 will be faster toward the top end of tach and 3.73 will be faster at bottom end. Neither will be different enough to show a different time on the stopwatch.

 

[Je1279]

I've skipped through most responses to give you my opinion based on ~2 years of experience. If you have the option, get the 3.73. I've been able to get ~19mpg highway on long trips with a 2" level and 34x11.5 E rated LT tires. Around town with my setup is ~14-15mpg, but damn, the 5.0 3.73 combo is all sorts of fun when you mash the go pedal.

 

[TN_Ryan]

My truck came with 3.31's, and with the 22" wheels and the stock gears on a stock engine, I averaged around 19MPG in the mountains of East TN. I put 3.73's in the truck, everything else remained the same, and the truck still averaged 19 MPG. Now with the Whipple, that's a different story

Although, the day after Christmas, the wife and I jumped in the truck and drove little over 2hrs south to Birmingham to pick up truck parts...averaged 20.6 MPG all the way there and back. Was pretty happy with that to say the least...with all things considered of course

 

[TacoJon]

My truck came with 3.31's, and with the 22" wheels and the stock gears on a stock engine, I averaged around 19MPG in the mountains of East TN. I put 3.73's in the truck, everything else remained the same, and the truck still averaged 19 MPG. Now with the Whipple, that's a different story

Although, the day after Christmas, the wife and I jumped in the truck and drove little over 2hrs south to Birmingham to pick up truck parts...averaged 20.6 MPG all the way there and back. Was pretty happy with that to say the least...with all things considered of course

Hoping that is the case for me too. With it being -10 deg F outside, you gotta idle your truck to warm it up, MPG is shit. So I can't really get a good idea on MPG until it warms up. I suspect a small highway drop in MPG though.

 

[vst]

I have a SuperCab with 5.0 4x4 and I average about 22+ but my drive to work is about 30 miles and on highway that has a speed limit of 60. On regular highway doing between 70 and 75 I get about 20 mpg. Truck feels plenty fast but I’m coming from a gladiator that was on 37’s

 

[TacoJon]

I have a SuperCab with 5.0 4x4 and I average about 22+ but my drive to work is about 30 miles and on highway that has a speed limit of 60. On regular highway doing between 70 and 75 I get about 20 mpg. Truck feels plenty fast but I’m coming from a gladiator that was on 37’s

What gears do you have? My old 2013 Tacoma never really got above 18 mpg so having all this power and getting 20+ mpg has been really nice.

 

[vst]

What gears do you have? My old 2013 Tacoma never really got above 18 mpg so having all this power and getting 20+ mpg has been really nice.

Sorry 3.31

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