Rear end Swap for MPG?

As I understand, the 2013 Tundra had 4.30 rear end gears. I personally have not the need for that low of a gear. I could use a 3.73 gear and it would be beneficial to me.
I called the local dealer and said that the 4.7L trucks came out with a higher rear end gear but I couldn't use it, I would also have to change the front differential gear as well.

Has anyone been through this?

 

Welcome. Is your Tundra 4wd? If so then you would need to change both front and rear to be able to continue to use 4wd. If just a 2wd obviously not. I'm not sure how much gas savings you would get by going to a taller gear.

 

Don't chase that dog...complete waste of time. What very limited MPGs you gain will never pay for the cost of the swap.

There's no magic bullet for MPGs other than slowing down or driving another car. Gotta pay to play...

 

+1

 

Yep. People chase better mpg and spend more than they save to do it.

 

I wouldn't do it. You run the risk of making it worse because it may not want to stay in overdrive from "lugging" the engine.

 

Is your truck completely stock? Are you running heavier wheels and or larger tires? Changing gears to 3.73 would be an absolute waste of time and money. There’s plenty of data from members here and other owners of 2nd and 3rd gen tundras about the lack of fuel economy. If the mpg bothers you that much, perhaps you need to sell the truck.

 

I have 4.10 gears sport package..

 

What gearing is used on a 2011 SR5 4x4 with tow package?

 

Buy a Prius if you want MPG.

 

4:30

 

You would be spending $1-2k for the parts and labor to install. That $ would buy a ton of gas.

 

The 4.6L and 4.7L powered trucks have a different rear axle. The 10.5" unit behind the 5.7L trucks doesn't have too many gear options and 3.73 gears do not exist for it. For a few years 5.7L trucks were made without a tow package and received 4.10 gears. Going down this route is not worth your time.

 

The truck is already turning 2000rpm or so at 80mph on the interstate, I can't imagine lower rpm providing enough torque for cruising let alone being lower enough to substantially change your fuel consumption.

 

Put the pen to paper and figure out if it's worth the gamble/effort or not.

15000miles/yr ÷ 17mpg = 882 gals of gas @ $2/gal = $1764.

15000miles ÷ 20mpg = 750 gals of gas @ $2/gal = $1500

$1764 - $1500 = $264 per year in fuel savings

If a regear cost you $1000, it will take roughly 4 years to just break even on gas savings - assuming you actually achieve a massive 18% increase in avg. MPG.

Timing of the Return On Investment will vary as any/all of these factors change: miles driven, price of fuel, cost of regear, and actual mpg efficiency gained/lost. More miles, higher price of gas, lower cost of regear, or greater mpg efficiency gain will see a faster return, while fewer miles, cheaper gas, higher cost of regear, or lower mpg efficiency gain will take longer to recover.

Obviously if the change for whatever reason results in fewer mpg than you're currently getting now it will be totally wasted effort and an ongoing negative $ return on the investment to regear.

 

If you do change gears. You will have to reprogram the transmission other wise you will dump extra fuel into the engine or run lean witch wont help at all. The gearing is all done by the factory for the optimization of the setup . Unless your changing tire size dont change your gearing for mpg. It will be to much of a headache and thousands of $. It will not be worth it