Regearing my regular cab

Going to be regearing my Tacoma very soon. Trying to decide if I want 4.56 or 4.88. 3rz engine 5 speed. I will be using this for mainly overlanding trips. Long trips mostly highway.

With 4.56's @ 75mph engine rpm is 3054 with 32" tires

4.88's @ 75mph engine is at 3268.
Only about 200 rpm difference.

I have a regular cab with 32" tires. May upgrade to 33's someday. I have heavy duty bumpers, winch, skid plate, fiberglass cap. A lot of added weight. I'm primarily concerned with fuel mileage and regearing. Would the lower rpm of the 4.56's be more beneficial for fuel mileage?

 

Only thing i can contribute is a dyno on the 5vz engine.
i think having the 4.56 GR would get you better gas milage, so long as you don't punch it.

4.88GR would be better if you're moving heavy loads, no?

 

For what its worth I had 94 pickup 4.88 on 33's. It didn't do much for me. So when I got a Tacoma I went 5.29 with 33's and love it. Its not my DD though. I don't think you'll feel a whole lotta difference with the 4.56's and as expensive as it is you wanna get it right the first time...

 

For overlanding, fuel mileage is a priority, not so much rock crawling. I'd stick with 4:56. Your fatigue levels on 4:88's will be a lot higher.

 

What do you mean by fatigue levels? I have 32" tires right now and 4.10's. The truck pretty much turned into a 4 speed around town (empty bed too). On the highway it has no problem cruising at 75mph...unless I encounter a hill lol.

 

Also, with the gear calculate on marlin crawler website, it says the difference between 4.88 and 4.56 is only about 200 rpms around 70 mph. Think that will make much difference?

 

The 4.56 will be such a minimal change in how it feels. I bet you'd gain less than 200 rpm too(with the 4.88). With a huge jump in gearing for me I only gained 300 rpm tops at cruising speed. 60/65 mph.

 

3000 rpm with the 3rz at 70mph is around the top range of my comfort level. 3300 would be uncomfortable. Just speaking from experience. Plus, any little bit of RPM at that speed is more points off your mpg. Just my opinion.

 

So you have 5.29 and 33's on your regular cab? Mine isn't a daily driver either but I plan on taking some long trips out west with it. So you would recommend 4.88's? I have 32x11.5 tires right now. I might go 33x10.5 but not any bigger than that. I do have a lot of weight. Heavy duty bumpers, tire carrier, full 3 piece skid plates, winch, cap on the bed, probably going to add a roof top tent too.

 

Absolutely 4.88's!! If I wanted to regear for say 31's I would go 4.56's and some tacos even came stock with 31's. Other than that I don't feel it's a big enough jump to even consider regearing... Going with 4.56 that is..

And yes I have 5.29's on 33's. When my speedo says 70 I'm at 66 mph running at 2780 rpm via scanguage!
Edited****

 

I'd run smaller tires. 31" and 4:10's are perfect. While 32" - 33" tires are only marginally larger in diameter they are substantially larger in mass. Fuel economy and 33" tires are mutually exclusive. If you are sold on the 33" tires though I'd go with 4:88's. With 4:56's you only have the option of 32"s while with a 4:88 set up you can choose either tire size based on your needs.

 

I have 5.29's and run 285-75-16's (33's) and have an auto trans. On the freeway, I'm turning 2750 rpm's @ 70 mph.
There are many accessories on my truck and I'm currently getting 16.5 mpg. My truck weighs 3650 and is a DD.

For you having a 5 spd trans, I think 4.88's would be good for you w/ 33" tires.

Just my opinion... hope this helps you.

 

I gotta change my previous statement about my rpm! Just drove my geared rig around. At 70 on the speedo which is 66 mph I'm at like 2750+ rpm at 75 on the speedo 70 mph I set at 2880+rpm!
I don't know why I thought I was running 3k rpm. Here in Oregon the interstate is only 65mph and highways are 55mph so the gained rpm is not at all a problem...

 

I found this helpful. If you know your transmission gearing that helps too. Otherwise do the math in 4th gear which is 1:1 ratio.
http://www.ringpinion.com/Calculators/Calc_RPM.aspx#Transmission
I recently went from 4.10 to 4.88. Different tire size and motor than you though, so use the calculator and see what you come up with.
Mine at 75 is 3100ish in 5th gear. I couldn't be more pleased with it.