Putting efficiency aside, it's all about gear ratio width, or spread. From the tallest to the shortest ratio. The 6-speed has a spread of 5.67. 8-speed 7.14. A 25% better spread. Remember back as kid, moving from a 14-speed to a 21-speed. That was a big deal. Because now we could climb some serious hills. At a crawl, but not having to get off the bike was awesome for the first time.
Which gets into the second major benefit for serious off-roaders like you. Crawl ratio.
6-speed: 34.1:1
8-speed: 41.5:1
For comparison.
4Runner 34:1
Basic Wrangler 39:1
Rubicon Wrangler 73:1
No it's not. I think you misspoke here or I might not be understanding. The 8-speed is geared much lower, even on account of the 3.307 rear end. Looking at this
effective gearing table (which includes the transmission and rear end), it's the 6-speed with a 4.88 that comes closest to the 8-speed with stock rear end.
I get your point on the highest gear. But if we had software that limited the highest gear to 7 in the 8-speed, there would be no other mod necessary! The 7th gear effective ratio is not so low such that it couldn't turn a rig that has AT tires, rack, and lift either. It really would be nicely setup.
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This thread was a month or so ago, I'm not sure what gear ratio calculator you're using. Not saying you're wrong, it's just I came up with different numbers, from what I remember.
Either way, I've now driven a 8 speed, with and without a bumper and lift, and I promise the 8 speed sucks just a ltiile worse than the 6 speed before it is regeared. It's about 150 RPM lower, and that is enough to keep the torque converter unlocked most of the time.
I can already tap into our ECUs and watch everything happening. Your gear calculators aside, the 8 speed is building a lot of excess heat and putting more load on the engine, making more wear and less MPG. When you can see your timing, air/fuel, etc, real time while driving down a highway, it moves you into a whole new level of understanding what really matters. Plus it's fun to turn the truck off with a laptop.
8 speed is not even sold on 2017 200s in Australia. It's just there to compete in America, because more is better in America. Just wanted to say that again.
I think the 8 speed is better than the 6 speed if both are regeared, and I think the 8 speed is better under a stock truck than the 6 speed under a stock truck.
But the 6 speed with stock gearing is better under a modified truck, than a 8 speed with stock gearing under a modified truck.
That real world driving, which is what we've been kind of going back and forth over. A gear calculator isn't the do all end all, your not taking into account the T/C lock timing, the 5.7s power band at certain RPMs, engine load, or changes to aerodynamics.
But again, I don't care about crawl ratios, your number of a wrangler rubicon was the manual. The auto is about 46:1. But autos almost double your usable crawl ratios over a manual. Gearing is kinda my thing, I've regeared close to 60 trucks, and quite a few with multiple sets. That's why I'm a little passionate about this, because if heard this argument before, and it only works on paper.
What I keep caring about is minimizing unnecessary shifting and limiting riding on the highway with the TC unlocked for miles on end, but also keeping engine load in check. Do you know when yours is unlocked?
