[eco-jeeper]

Hey y'all,

First off I want to say thanks to you folks, I've been gleaning ideas from this website since last summer and you are an inspiration to me! This is my first post though, I created account just to share my success story with you!

On a 68 mile interstate drive last night I got a calculated 28.5 MPG using the fill up, drive, fill back up, divide miles driven by gallons used. For reference I got 21.8 MPG on my last full tank fill up after just driving around town ~340 miles.

This was on my 93 Jeep Cherokee. Last week I purchased this Jeep from someone who had done several mods on it, but they were mostly intended for offroad use, though several have helped fuel economy. Some engine components were damaged from mud and replaced.

How was 28.5 MPG possible?

- The engine is a four cylinder 2.5L
- The top half of the engine was rebuilt
- Two new belt pulleys, rebuilt alternator, new water pump
- Installed aftermarket electric fan (from a semi truck haha)
- The engine supposedly had a "full tune-up"
- Manual transmission
- High flow aftermarket exhaust with shortened exhaust pipe
- Tires were oversized from stock 215mm (27.7 inches tall) to 31 inches
- Gears were not reset, so the Jeep is traveling faster for the same engine speed (speedo reads 60, actually moving 65, from calculations and empirical tests)
- Tires were inflated to 44 PSI (max sidewall 50 PSI)
- I never exceed 65 MPH (well for the second half lol)
- I used a vacuum gauge
- If I wasn't going uphill I never opened up the throttle to less than 10 PSI
- If I was climbing I allowed 2 PSI less vacuum per MPH I dropped below 65 MPH
- In other words, I stayed at 10 PSI at 65, 8 at 64, 6 at 63, etc..
- If I got down to 60 MPH I opened the throttle fully (0 PSI). I did this because it takes a LOT more time/fuel/concentration to get back up to 65 MPH while staying above 10 PSI vacuum

It seems that in my particular setup, 65 MPH is the sweet spot. My Jeep vibrates heavily at 70, and at 60 on hills I have to open the throttle fully just to keep an even speed.


So what do y'all think?? Installing a tach today!