Gearing: V6 & 33’s

[Flesh Eater]

I searched a few key terms and it brought up build threads. Some of you have a lot of information to sift through and I’ve also noticed more guys build V8’s here than V6’s.

Does anyone have experience re-gearing for 33’s who also runs a ton of highway miles ranging up to 85mph cruising?

I’m ultimately wondering if these V6’s perform better at a higher RPM at cruising speeds or if I should try to maintain it around 2,400 RPM’s at 80-85 mph?

Any input is welcome. I’ve just noticed a lot of shifting out of overdrive with 33’s and 3.73’s. I was considering 4.30, but some say to go deeper…I just don’t want this vehicle screaming at high RPM’s for hours on end. According to the calculations 4.30 seems tolerable at the higher end of my cruising speeds.

Thanks!

 

[OLD BOB]

When I changed the frame on my 04 I also changed the gear ratio from 3.9 to 4.56. This made a huge improvement in drivability with 285/75r17 tires which are 33 inch in diameter. I built the 4r for a ranch hunting vehicle and put 10 ply mud terrain Coopers on to help keep from having flats.
I drive it about 300 miles a weekend back and forth to the ranch but with the type of tires and suspension that I have I keep the speed to about 65 mph. this is about 2200 rpm. Very hilly country at about 3000 ft elevation but I don't have a lot of down shifts unless I have a stiff head wind.
I don't think that the 4.56 ratio would be too low but you would likely get very poor fuel economy at 80mph.
I have done a lot of gear changes in my 60 years as a builder and never had an issue with too much gear. A heavy load on and engine is much harder on it than a few extra rpm.
rd

 

[Syr4RinNC]

I have a V6 with 255 80 17s. I really have not noted any significant decrease in power. I get about 18.5 combined MPG and 19.5 highway. (hand calculated as the speedometer and odometer are off with the inc tire size over stock).

Id like a better crawl ratio when off roading, but for highway driving, no issues at 33s. Certainly part of it is how heavy your tires, add ons are

 

[Flesh Eater]

I have a V6 with 255 80 17s. I really have not noted any significant decrease in power. I get about 18.5 combined MPG and 19.5 highway. (hand calculated as the speedometer and odometer are off with the inc tire size over stock).

Id like a better crawl ratio when off roading, but for highway driving, no issues at 33s. Certainly part of it is how heavy your tires, add ons are

I also have not noticed a difference in drive-ability. I’m looking at lockers and figured I’d re-gear at the same time. Was going to step up to 4.30 to get a little lower than factory set up.

I also get what Bob was saying above. Put the stress on the diffs and not the engine/trans. I just cannot drive 65mph when the speed limit is 80mph. Haha!

 

[Hi-desertT4R]

There’s a great gear calculator on grimmjeeper.com. I plan on regearing soon and according to the research I’ve done, regearing to 4.30 with 33” tires will essentially put you back to “stock” ratios. I’m hoping to gain back some of the low end power and cure the transmission searching for gears on the highway. I want to go with 4.56 because I do more trails and local driving with it vs. long highway commutes.

 

[Inv4drZm]

Personally I wouldn't spend the money to regear with a V6 and 33s. Maybe not even with 35s unless you are way loaded down with armor and bumpers and gear and have a headwind.

I've always had better results with manual throttle control vs cruise control for interstate travel, at least for the steep uphills.

But I live in Kansas where its pretty flat driving.

 

[Flesh Eater]

There’s a great gear calculator on grimmjeeper.com. I plan on regearing soon and according to the research I’ve done, regearing to 4.30 with 33” tires will essentially put you back to “stock” ratios. I’m hoping to gain back some of the low end power and cure the transmission searching for gears on the highway. I want to go with 4.56 because I do more trails and local driving with it vs. long highway commutes.

I’ve been running that calculator for years.

This would be much cheaper if I trusted myself. I’ll re-gear my dedicated off road rigs, but I’m not trying it in this. Same concept, but I don’t want the doubt in the back of my mind. I just did a set of Toyota 3rds to 5.29 for a Sami.

However, running numbers and stuff for a dedicated toy rig is so much different than this vehicle. I don’t even think my toys can hit 85 mph! I’m pretty sure there’s a lot of people here who probably use their 4Runners as overlanding vehicles more than dedicated off road rigs. Just hoping for some real world experience here.

Plus, I only drive this vehicle like 4-5 times a year, which is probably why I don’t notice the power loss. I just notice it shifting in and out of overdrive non stop at cruising speeds. It’s terrible.