Issues with 5.29 Gears

If lugging and low rpm were the key to great fuel mileage, then 50 mph in 6th gear at 1740 rpm would generate fantastic fuel mileage. It typically doesn’t.

 

I don't think your example is wrong, that cruising down the highway in a stock vehicle with tall gears isn't gonna get the best mpg, but you're ignoring the fact that a modified vehicle has the possibility of gaining mpg. A lifted truck with large tires can be similar to a trailer in that it has much more resistance. As I said, I actually get lower rpm with the regear because the truck needed torque on highway, and the stock gears were so tall that it had to choose between about 2.5k or 4k, but the shorter gears lets me cruise at about 3k rpm. It's possible I'm actually getting much better mpg, but I'd have to have done way more trips with each gear set to know the difference. I just fill up and don't worry about gas

 

what size tire? I'm 285x75x16 and spinning 2500rpm at 65mph

 

AT vs MT. Different overdrives.

 

Noted, Wish I had a MT

 

How does one cough up 3000 dollars with no research?

 

Unfortunately, modern vehicles can't just have a gear swap and away you go. You also have to address the computer, as it's reading a lot of different things that changing gears affects. The CPU has to be updated with the new gear ratio.

 

OP what shop did you go to for the installation?

 

I found the video on how engine rpm affects efficiency. It's specific to manual transmissions, but the concepts apply to an automatic as well.

https://www.youtube.com/watch?v=iNspNdVkslA

 

I’m running 285/75r17’s with 4.88s and a tune, and my mileage still sucks
With bigger tires, it was totally worth it though. Goes up hills and shifts so much better

 

Was this a gas saving video or just general engine efficiency? I can see an engine being “power” efficient but not gas savings efficiency

if constant rpms stay the same…a lower load vs a high load can be compared. Low load will always net less gas usage then high load.

In Tacoma fuel usage the Tacoma engine is horrible on low torque under 2k rpms. So if you had to increase speed to 65…low torque would be pushing the gas pedal down further and longer. This would be higher load. If Tacoma’s had fat torque numbers down low under 2k….you would barely need to touch gas pedal and for much shorter duration.

Think of your gas pedal as your fuel meter. The more you push, more fuel. The longer you push, more fuel. Ideally it all comes down to whoever can push the gas pedal the least amount of times.

In gearing, higher gears would increase torque per gear. So shorter gas presses to increase speed would be the gas savings part.