Issues with 5.29 Gears

As many people have said, these are all normal things.

1. Get a tune, it will fix your top speed governor, and make the shifting much better.
2. Mileage will improve once you get a tune to take advantage of the gears.

I had the OTT tune, and am on 34's. Got 529s and while it felt a little better in certain areas, it really didn't come together until I had the tune updated to the 529 gear tune.

Mileage won't ever be great, accept that now. I get basically the same highway mpg going from stock to 529s. Around town the 529 MPG is a little worse.

 

1. Speed limit. Tune will cure this!
2. MPG. Seems very close to correct to me. My best MPG is 63 MPH. I can get 17-18MPG here if I am super careful and DO NOT use cruise. This is actual not indicated speed. Per calibrated Scanguage
3. Shifting. Tune will cure this too! Or at least make it WAY better.

I love my 5.29s. I can cruise at just less than 2K RPM @~65MPH and can cruise about 80MPH at about 2500 RPM. Horrible MPH at 80 but it does it very easily...

 

Not 5.29’s but 4.88’s here at 65 -70 rpm’s are 2000
mpgs I don’t care

 

I can do that with the stock setup too. Just put it in S5.

 

You're overgeared. Taller tires might feel better. But your mpg is fucked. Maybe try a tune and running some skinnies. 255/80/17 is a great size on these trucks.

 

Why would you like to hear your truck screaming for mercy at 65?

 

guess he needs bigger tires to balance it out

 

If your truck is screaming at 65 it's best to take it out of 4lo

 

Yes I did and nowhere in the OP it mentions 80 mph. You can assume anything you want, sure.

 

Why do people think that lower gears and thus higher rpm on the hiway results in better fuel economy?

 

In defense of that pov, it's definitely possible.

Have you ever hit a yellow light in a MT and don't downshift? You can push the gas to the floor and barely increase speed.

If you have enough weight and large enough tires, you will waste fuel.

 

There is not a 1-1 relationship between throttle pedal displacement and the amount of fuel being used by the engine. There are many reasons, but the biggest one is that the ECU will inject gas dependent on the amount of air entering the engine and that is dependent on the engine rpm (and throttle setting).

Also I think this is a real edge case. Who drives like that on a regular basis?

 

Haha no I'm not cruising at speeds like that, however it is nice to be able to speed up to pass semis. This highway I'm talking about is one lane in each direction so being throttled at that speed makes it difficult to safely get around trucks.

 

no effin way

 

Because higher rpm doesn’t always hurt mileage and sometimes helps. That said, I would never regear hoping to boost my mpg. Do it for the performance benefits and hope for the best on the mpg department.

 

OP didn’t read the mega thread

 

3 post in and he regeared

 

You can try it in an old vehicle without computer assistance, and still waste gas because you don't have enough torque. Personally I don't think any tacoma is gonna experience that unless they've gone very large on tires.

I have 33s and have crossed country with it once at factory and again with 5.29s. I didn't notice any mpg difference, but I towed a trailer that's a wind sail. Though my rpm actually stayed much lower with 5.29s because there's so much distance between gears that it was able to find a sweet spot. instead of 4k I ran about 3k rpm when going west with the typical headwind.

 

Everything I said is true of carbureted engines as well. There’s a good Engineering Explained video that explains under what conditions an internal combustion engine is most efficient that can’t find right now. The gist of it is that engines are most efficient at low rpm and high load. This is why modern cars have very high gears for cruising down the hiway.

Towing a “wind sail” causes fuel economy to decrease primarily because of the aerodynamic losses. Any difference in engine rpm is likely negligible in comparison.

Fuel economy is affected by engine efficiency, amount of brake use, aerodynamics, tire rolling resistance, drivetrain friction, driver behavior, and perhaps a few other things.