rear end ratio and mileage

If I have this right, the current Tundra comes standard with a 4:30 rear end ratio.

I have resisted buying a Tundra for years even though the local dealer is a good friend. Mileage has been the only reason. I talked with him about ordering a truck but neither he nor I knew any results of having a different rear in ratio from the standard factory one.

Does anyone have a Tundra with a more everyday rear end ratio such as 3:55? How did that affect your mileage, performance, and towing?

 

I dunno that anyone has tried that. Everyone that does gears goes to 4.88 or 5.29 as they’ve gone bigger tires

you can get 15+ mpg if you drive reasonably. Some of the SC trucks are even better than that

 

The last 2 gears in our trucks are overdrive. I don't think a gear change for MPG would be worth it. The truck would be a dog and not perform well, doubt it would ever shift out of 4th gear. It would greatly reduce towing ability. Add the expense of the gear change and labor....you would be in the hole $ wise.

If MPG is of any concern a Tundra is not for you. They can get 18 or 19 mpg with stock setup and tires on the highway. You are not going to make a Tundra a gas sipper.

 

Thats going 65-70mph tops....and flat.
ive gotten 18mpg once. not many cars on the freeways and i set the cruise control at 68mph. got great mileage when it was flat, but dropped once we got into the hills.

 

This is the type of information I am looking for. Thanks.

I should have mentioned that my towing days are over and the horses are sold. Most of my driving is around town with a once or twice a year ride out west to hunt. Maybe that extra information will help with my question.

If I order a truck, it will be a loaded model with no extra add ons after the purchase. It will stay stock.

 

I wouldn't let fuel mileage be my deal breaker on either getting a Tundra or one of the other 4 half tons out there...

If you're worried about fuel mileage, do the math for what, 3 mpg +/- over time. To me, it's worth the reliability. And i'm sure with any change in gear, it would take a couple years or so (guessing) to make up for the difference in fuel costs. Just my .02

 

That's not only in flat areas. I was in SLC last weekend and I got 18 MPG on the I-80 return trip to Wyoming. That is an elevation change of about 3000 feet. Stock tires, cruising a bit under speed limit, but not much below it. I stayed between 65 and 75, so at times I was at the speed limit.

I understand that fuel mileage is a concern, but how much better is the MPG in other things you are considering? If you run some numbers then a few MPG difference might not be as big a deal to you. Then again, it might be exactly what you figured. Everyone has their own reasons for buying what they buy.

To put the cost difference in perspective I have copied a little number crunching from another post I did on here ->

...people get all jazzed up about a bump of 3 MPG between brands, but I would ask you to do some quick and easy math before getting too crazy.
We will use $3.00 per gallon fuel cost, the higher industry average mileage of 15,000 miles per year, and a 15 MPG average overall. That's 1000 gallons for $3000 per year and $250 per month. A 20% gain in MPG would be a 3 MPG boost up to 18 MPG (numbers may vary, but we are using easy math here) so that drops you down to 833.33 gallons per year and an annual cost of $2500 and $208.33 per month. That is less than $50 per month. Nothing to sneeze at, but if 50 bucks is gonna make or break your monthly budget you are mismanaging your funds in ways that fuel savings are the least of your worries.

 

Gotta compare transmission * rear end to compare. An F150 is an easy example because it's the same OEM tire size. A 6-speed F150 would need a 3.659:1 rear end to match a Tundra's overdrive ratio so if it's purchased with the optional 3.73 it is actually shorter gearing than the Toyota. To match top gear rpm to a 3.55-equipped F150 6-speed, a Tundra would need a 4.173:1 rear end. The 3.55 F150 at 70 mph would spin just under 1900 rpm; the Tundra, about 1950 rpm.

Comparing to a 10-speed F150 with its even taller overdrive, at 70 mph in 10th gear it would turn about 1750 rpm.

I think the main reason for the lower mpg than competitors is component drag. Tundras still have a mechanical cooling fan (not electric), hydraulic power steering (not EPS), bigger bearings just about everywhere, an extra bearing on the 2-piece driveshaft, and so forth. Plus no direct injection, or cylinder shutoff, or lower air dam to snag things.

 

The Tundra is also a fair bit heavier than the half-tons that are made with aluminum and possibly taller in stock configuration.

 

Just so you can crunch the actual numbers if you would like, here are the different MPGs. Keep in mind that a turbo demands premium fuel, so that is going to close the cost gap some as well. https://www.eia.gov/dnav/pet/pet_pri_gnd_dcus_nus_w.htm Link is for fuel prices by type. You can play with the theoretical MPGs of various trucks and the cost for your predicted annual mileage to get an idea of what your savings per MPG would be for the varying fuel grades.

 

If you were to change that gear to a 355 your truck would lay down below 1500 rpms at cruise and not want to go...then it would downshift...would probably up/down shift constantly.

 

I’d also recommend comparing numbers off Fuelly and not just EPA numbers. People claim f150 and Silverado get way better mpg but real world not so much.

 

I hear you on that. EPA numbers are not the most reliable. Still, the whole point being illustrated is that a real world improvement of a few MPG isn't exactly a budget saving amount of money. If you have to use premium fuel to gain those MPGs then it is an even smaller savings. People these days are so hung up on numbers on stat sheets, and they forget to look at the real world translation, just like you pointed out on the EPA numbers.

 

My Tundra with 4.30s runs about the same RPM in 6th gear at 70-80 mph as my F150 with 3.55s did. In fact when towing with the Tundra, I have to lock it out of 6th to keep it from constantly upshifting and then downshifting because 6th is pretty tall.