After reading through the many, many threads on 35s, 2.5" lifts and gear upgrades, I thought I'd track some quantitative data related to my own experience that might provide more than general observations for the person considering these updates to their JK. It seems to me that most questions are about appearance, miles per gallon changes, and gear upgrades. So, here's my attempt to hit all those topics.

My BEFORE tests were conducted in my 2013 Jeep Wrangler Sahara JKU automatic. Prior to this work, it had only slight performance modifications (K&N FIPK kit, a Borla catback exhaust), it's heavy (Rampage front and rear recovery bumpers, and a Quadratec 9500is winch), and I live in Colorado where it's harder for humans AND Jeeps to breath. In BEFORE tests the Jeep had stock suspension, 18" MB Wheels TKO, 275/65/R18 Duractracs and 3.73 gears. For my AFTER tests, I added a 2.5" AEV Dualsport lift with geo brackets and a Synergy front control arm, 17" ProComp Series 7069 wheels, 315/70/R17 Duratracs, and 4.56 gears, all installed and Procal'd by Trail Jeeps* in Golden, Colorado. For all tests, I drove the same routes and maintained the same driving speeds and acceleration rates as best I could.

So, maybe this is helpful stuff to those considering a similar setup. Anyway, here goes:

1. MILES PER GALLON
IN TOWN (51 miles of around town driving)
- 14.7mpg before / 14.5mpg after

INTERSTATE (56 miles interstate loop averaging 75mph)
- 18.7mpg before / 16.2mpg after


2. RPMs
BEFORE
- 2500 RPM @ 75mph in 5th gear
- 3000 RPM @ 75mph in 4th gear
- 2000 RPM @ 60mph in 5th gear
- 1600 RPM @ 40mph in 4th gear

AFTER
- 2800 RPM @ 75mph in 5th gear
- 3400 RPM @ 75mph in 4th gear
- 2200 RPM @ 60mph in 5th gear
- 1850 RPM @ 40MPH in 4th gear


3. HEIGHT MEASUREMENTS (I was surprised how much more than 2.5" I actually got, and glad that the lift fixed the majority of the front-to-rear rake I had)
(ground to fender at the center of the tire)
BEFORE
- Front Driver: 34.5"
- Rear Driver: 36"
- Rear Passenger: 36"
- Front Passenger: 34.5"
- Front Differential: 9.75"
- Rear Differential: 9.25"

AFTER
- Front Driver: 39.5"
- Rear Driver: 40.25"
- Rear Passenger: 40.25"
- Front Passenger: 39.5"
- Front Differential: 11"
- Rear Differential: 10.75"


4. PICTURES
And finally, for the curious, here's the visual difference, complete with my wheelin' buddy so you can see the difference in height compared to him as well as the rapid effects of Fall in Colorado.

BEFORE


AFTER



* HIGHLY recommended for those looking for a great JK shop in Colorado.

 

Nice info!

I can't tell right now but, is your jeep a brown or like a burgundy color? What's it called? Can't say I've ever noticed a color like it before on a jeep. >.>

 

Thanks! It's called "Rugged Brown". It was an option in 2013, but I don't think they made many.

 

Nice report: thumbsup:

 

Very good review and info

 

Cool info. Nicely done

 

Thank you for your post.
It should help lots of jeepers make up their mind before mods.

 

Thanks! Been driving it around for a couple weeks now and I wouldn't change a thing! It's exactly what I was after. Everybody wants something different from their Jeep, but this one is perfect for me!

 

Great info!

 

good info. Im about to do gears. right now in cold weather im getting 17.1-19.2 mpg with 3.21gears, never higher never lower...of course im using the dash to tell me the MPGs is anyone else seeing these MPG with a 6speed/ lift/tires? with all that said im not worried about MPGs, just curious, about the autos MPG.