Ran4
Well-Known Member
- First Name
- Randy
- Joined
- Dec 7, 2019
- Threads
- 13
- Messages
- 295
- Reaction score
- 512
- Location
- Port Saint Luce FL and Charlotte, NC
- Vehicle(s)
- 2019 Sahara Unlimited
- Occupation
- Retired
- Thread starter
- #1
Yesterday we wrapped up a regearing of my 2019 Sahara 4-door. I've been running 35" tires (315/70R17 Falken Wildpeak ATs) on the Jeep for roughly the past 10K miles using the OEM 3.45 gear ratio coupled with the 8-speed automatic transmission. Throughout that experience, I had been claiming that this configuration is tolerable for both on, as well as off road. I still believe that. BUT...having made the huge leap from 3.45 to 4.56 gears, I simply could not be happier with the result! Not only have I been reintroduced to 8th gear on the highway, but the acceleration for passing and coming off a dead stop has been vastly improved. In addition to the performance improvements, its looking like the fuel mileage has made an impressive increase from roughly 17mpg (ish) combined City/Highway to around 19.5mpg (I've put only about 100 miles on the Jeep since the regear with most of that being on the highway in access of 70mph. Time will tell where the overall fuel mileage improvements will settle out).
With the 3.45 gears, the Jeep's 2.0L was turning 2200 RPM at 75mph in 7th gear. With the new Dana/Spicer 4.56 gears, I'm seeing 2350 RPM at 75mph in 8th gear. As I said above, the OEM 3.45 gears can and 'will' turn the 35" tires 'good enough' for daily driving as well as for moderate off-roading (I've earned four BOH medallions with that configuration), but having the 4.56s under her is like getting a whole new Jeep. I should mention that my Jeep is a daily driver, and I routinely make the 600+ mile drive from Charlotte, NC to south Florida. For 'my' purposes, I believe the 4.56 gear ratio on 35" tires and the 8-speed auto trans hits the sweet spot. If, on the other hand, my Jeep was primarily for off-roading with limited on-road driving, perhaps 4.88, or even 5.13 gears might fit the bill. But for me, this 4.56 Dana gear upgrade is perfect.
Sending out a 'thank you' to fellow forum members @Taznc, @MadDog27, and @jdubya421 for assisting with the installation (others helped as well that are not forum members), and a very special THANK YOU goes to @chevymitchell for showing all of us how its done. His attention to detail, and his 'go the extra mile' character is rare these days. Thank you, Sir!
With the 3.45 gears, the Jeep's 2.0L was turning 2200 RPM at 75mph in 7th gear. With the new Dana/Spicer 4.56 gears, I'm seeing 2350 RPM at 75mph in 8th gear. As I said above, the OEM 3.45 gears can and 'will' turn the 35" tires 'good enough' for daily driving as well as for moderate off-roading (I've earned four BOH medallions with that configuration), but having the 4.56s under her is like getting a whole new Jeep. I should mention that my Jeep is a daily driver, and I routinely make the 600+ mile drive from Charlotte, NC to south Florida. For 'my' purposes, I believe the 4.56 gear ratio on 35" tires and the 8-speed auto trans hits the sweet spot. If, on the other hand, my Jeep was primarily for off-roading with limited on-road driving, perhaps 4.88, or even 5.13 gears might fit the bill. But for me, this 4.56 Dana gear upgrade is perfect.
Sending out a 'thank you' to fellow forum members @Taznc, @MadDog27, and @jdubya421 for assisting with the installation (others helped as well that are not forum members), and a very special THANK YOU goes to @chevymitchell for showing all of us how its done. His attention to detail, and his 'go the extra mile' character is rare these days. Thank you, Sir!
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