MPG upgrades for 98 jeep wrangler

TexasJoe

New member
I have a 98 wrangler Sahara edition with a 4 inch lift and 33 inch mud terrain tires. I'm moving from Alabama to Texas and Ill be traveling back and forth frequently but I don't want to get rid of my baby. So, I will have to make some upgrades to help with MPG to make the trip a little less heavy on the engine and a little less expensive in the long run. What upgrades could I make to help?
 

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Tires and rims
 

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The best upgrade would be a cheap commuter car LOL. Other than that, regear the axles to get the engine operating back in the proper RPM range for best mileage. Too tall of overall gearing will cause the engine to lug and use more fuel.

Consider a high-flow intake box setup and a 62mm throttle body. Not a whole lot can be done to improve the efficiency of a brick, and you'll never recoup your costs of upgrades in fuel savings.
 
The best upgrade would be a cheap commuter car LOL. Other than that, regear the axles to get the engine operating back in the proper RPM range for best mileage. Too tall of overall gearing will cause the engine to lug and use more fuel.

Consider a high-flow intake box setup and a 62mm throttle body. Not a whole lot can be done to improve the efficiency of a brick, and you'll never recoup your costs of upgrades in fuel savings.

I wasn't planning on a huge change haha I'm not tryin to get 20 mpg or anything, I know that's not possible. I just want it to perform better, smoother, and more consistent
 

No the intake is relearned within 500 mi. I put 2500 into CAI, 63mm TB, 2.5" CATBack, headers and e-fan. and picked up 1-2 mpg. Honestly the best is to have the correct gearing, speedo gear, smoother tires inflated properly. Second keep it at or below 65.i just revisited mpg info from my last 1100 mi trip. ~550 to and from.
The biggest improvement I saw was the e-fan. Above 35 it doesn't need to kick on so you regain the hp from the lost by driving the mechanical fan.

Miles. Gal. Cost. Mpg(cal). Mph/ gear/rpm
255.5. 13.77. 45.03. 18.55. 65/6/2100
123. 6.388. 23.67. 19.25
113.9. 5.964. 21.46. 19.09
53.3. 3.39. 12.20. 15.42. 70/5-6/2100-2500 hills
545.7


282.2. 16.6. 61.53. 17.0. 70/6/2300hills
172.6. 9.7. 32.39. 17.79
91.4. 4.9. 16.4. 18.6
546.2

For more consistent, clean air filter, run some Injector cleaner, put in new plugs gapped correctly. You could use single platinum plugs but I'd go with double Champion 7034. Also be sure your battery is good, cleaned along with all connections including the other ends of the grounds. Oh and clean your TB and IAC.

http://www.jeepforum.com/forum/f9/cleaning-iac-throttle-body-write-up-dummies-1114849/
 
Last edited:
No the intake is relearned within 500 mi. I put 2500 into CAI, 63mm TB, 2.5" CATBack, headers and e-fan. and picked up 1-2 mpg. Honestly the best is to have the correct gearing, speedo gear, smoother tires inflated properly. Second keep it at or below 65.i just revisited mpg info from my last 1100 mi trip. ~550 to and from.
The biggest improvement I saw was the e-fan. Above 35 it doesn't need to kick on so you regain the hp from the lost by driving the mechanical fan.

Miles. Gal. Cost. Mpg(cal). Mph/ gear/rpm
255.5. 13.77. 45.03. 18.55. 65/6/2100
123. 6.388. 23.67. 19.25
113.9. 5.964. 21.46. 19.09
53.3. 3.39. 12.20. 15.42. 70/5-6/2100-2500 hills
545.7

282.2. 16.6. 61.53. 17.0. 70/6/2300hills
172.6. 9.7. 32.39. 17.79
91.4. 4.9. 16.4. 18.6
546.2

For more consistent, clean air filter, run some Injector cleaner, put in new plugs gapped correctly. You could use single platinum plugs but I'd go with double Champion 7034. Also be sure your battery is good, cleaned along with all connections including the other ends of the grounds. Oh and clean your TB and IAC.

http://www.jeepforum.com/forum/f9/cleaning-iac-throttle-body-write-up-dummies-1114849/

Not sure what all these acronyms are... Not quite a mechanical wiz just yet.
 
Not sure what all these acronyms are... Not quite a mechanical wiz just yet.

CAI - cold air intake
CAT Back- exhaust from catalytic converter back is larger diameter and free flowing.
TB - throttle body
IAC - idle air control -it is on the throttle body.
E-fan - electric fan
 

CAI - cold air intake
CAT Back- exhaust from catalytic converter back is larger diameter and free flowing.
TB - throttle body
IAC - idle air control -it is on the throttle body.
E-fan - electric fan

Much better. Much appreciated.
 
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