Gas milage and drivability of 4.10 Rubicon gearing vs 3.45 Sport gearing

Dynomite1371

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Yep. I doubt I'll drop 6th until 55mph, and that is if I'm cruising. I'm pretty sure I'll only drop 6th when I hit the desired cruising speed, whether it is 60, 65, 75, or whatever. I won't accelerate with it, only cruise, especially when I go to 35's. It feels TALL.
After my first fill up last night then out on the highway, I was showing 18.4 on the current average cluster, after a few miles of cruise control driving set at 65mph.





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After my first fill up last night then out on the highway, I was showing 18.4 on the current average cluster, after a few miles of cruise control driving set at 65mph.
Thanks. I was hoping gas mileage would be an improvement over my TJ, but looks like it won't.

It will be interesting to hear some Sport mileage numbers.
 

DanW

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Thanks. I was hoping gas mileage would be an improvement over my TJ, but looks like it won't.

It will be interesting to hear some Sport mileage numbers.
We'll see. I see promise in what I'm getting with the 6 speed. On a drive that would yield about 17.5 in my JK (That's indicated, which is 1mpg better than reality), the JL, with less than 100 miles on it, showed about 19.8. I havn't had it on the highway for more than a short stretch, though. I also don't know if the indicator is as optimistic as the JK. If it is not, then the spread is even better than the 2.3 or so indicated.
 

wanderer

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Anyone know the ratios on the old 4sp auto?
 

Nkyzr2

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Depends on the engine and load. On my YJ, I gained 5 miles per gallon when I swapped the factory 4.10s out in favor of 4.88s. I wouldn't have believed it unless I hand calculated it myself. But it went from 13 MPGs to 18 MPGs instantly. Why? Because the anemic 2.5L engine was slaving to move the Jeep around on 33" tires with 4.10 gears. The 4.88s allowed the engine to work less to get up to speed and maintain speed once there.

On the modern JL, you'll never see a 5 MPG difference between gear ratios but you may very well see a 1-2 MPG difference if you keep the engine happy with deeper gearing. The ONLY time numerically lower axle ratios save fuel is if you live in Kansas and you never drive on hills.
Hmmm, did you swap the speedo gear or were you just seeing more miles on the odometer between fill ups? I remember seeing a 2 mpg difference on my TJ when I swapped from 4.56 gears to 4.88 gears. I didn’t change my speedo gear and I was actually putting more miles on the odometer than I was logging in real life... lol
 

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Hmmm, did you swap the speedo gear or were you just seeing more miles on the odometer between fill ups? I remember seeing a 2 mpg difference on my TJ when I swapped from 4.56 gears to 4.88 gears. I didn’t change my speedo gear and I was actually putting more miles on the odometer than I was logging in real life... lol
Yep, I did. I actually ended up with a colorful collection of those little gears trying to get it just right. :)
 

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After my first fill up last night then out on the highway, I was showing 18.4 on the current average cluster, after a few miles of cruise control driving set at 65mph.
Yy
After my first fill up last night then out on the highway, I was showing 18.4 on the current average cluster, after a few miles of cruise control driving set at 65mph.
What is the RPM?
 

zgn

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After my first fill up last night then out on the highway, I was showing 18.4 on the current average cluster, after a few miles of cruise control driving set at 65mph.
Did you get the manual or auto? I forget.
 

Dynomite1371

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Auto. It's a little rocket ship with new auto!
 

AZCrawl

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We should compare some RPM's at 50 and 70 MPH on the Rubi and Sahara.
 
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What is the most efficient rpm for the 3.6 Pentastar at 70 mph, on flat terrain at sea level ?
 
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The concept that is missing for a lot of people re: 'confidence in the market' is that confidence alone isn't a meaningful metric; what matters is 'confidence+time horizon'. Am I confident that the S&P 500 will go up 6% or more this year? No, I wouldn't bet a dime on that outcome. Am I confident that the S&P 500 will return 6%+ annualized over the next 15 years? Yes, I am, and I 'bet' most of my assets on that outcome.

History is on my side; the worst 15-year stretch for the S&P 500 of my lifetime was 2000-2015; this time period included the dot-com bubble bursting, 9/11, the financial crisis, housing bubble bursting, near-perpetual war, etc. Yet, the S&P CAGR over this time was 5.78% (including dividends). Basically the worst-possible scenario for the stock market over this time frame was STILL over twice the effective returns of paying cash for a vehicle (instead of financing at current interest rates). Obviously when auto loans were 8%, it was a different story, but auto loans are CHEAP now if you have good credit. My current loan is 1.99% for 5 years (PenFed).

Are there scenarios where stocks become worthless? Yup; all manner of apocalypses. But in any scenario where stocks become worthless, money in general is equally worthless; you'd rather have water, food, fuel, ammo (and a Jeep!) in these scenarios. So a Wrangler would just be my portfolio's hedge against a zombie apocalypse :jk::rock:
I have printed, framed and hung this on the wall beside the fireplace. It wouldn't fit onto a 'welcome' mat, nor could I find someone patient enough to do it up in needlepoint.... or else I would have! It's not the best way to live, but, like democracy, it's the best one we've got so far. Frankly, like democracy, it could use a few more visible defenders these days.

An unfortunate fact is that many people wrongly assume poverty to be the only possible outcome if their monthly income is 'x' dollars or less. It has nothing to do with their willingness to change or how hard they're willing to work, rather its a function of ignorance and thus solvable with some help. We're all ignorant of something. Let's be supportive of 'new' ideas that 'conserve' our wealth and every other resource that keeps life worth living - including fuel and other efficiencies in our Wranglers. Then, let's go let it all hang out on the trail. I'll bring the beer, a few sticks of firewood and my marinated beef ribs.... Efficiency matters, and can be leveraged to create future wellbeing/wealth.
 

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Heh, @Bald-faced Outlier, keep an eye for me and give me a wave if you see me...or pull me out of the mud...which ever is most suitable to the situation.
 

Jeep4Life

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Took a drive today 200 mile round trip. Got 20.5 mpg. I have now 2600 miles on my Rubicon. I changed the oil and filter at 1050 miles using Mobil1 full synthetic and a Fram filter for synthetic oil. I also run Shell V-Power 93 gas. One happy Rubi owner! :rock::dance:
 

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