getting better MPG and HP after lift

4

435Mj

NAXJA Forum User
Location
utah
what should i do after i install my RE 4.5 and some 32's to get better MPG and HP. i was getting about 16-17 MPG stock. and i know that will go way down after i lift this beast. so what are some inexpencive ways to counter act the larger rubbers? throtle body spacer,exhaust, air intake......any other ideas. cause this is going to be my DD and i need that gas milage. thanks for the help
 
xj_toker said:
what should i do after i install my RE 4.5 and some 32's to get better MPG and HP. i was getting about 16-17 MPG stock. and i know that will go way down after i lift this beast. so what are some inexpencive ways to counter act the larger rubbers? throtle body spacer,exhaust, air intake......any other ideas. cause this is going to be my DD and i need that gas milage. thanks for the help
Click to expand...


Regear.

Don't expect Hp mods to net you an increase in mpgs. They do, but they also make it alot more fun to be heavy on the skinny pedal, whick in turn lowers your mpgs even more. Just regear and call it good.
 
can you explane how the re gearing works. cost. and what i would need while running 31-33X10.5 R15 i belive i have a chrylser 8 1/4 in the rear and a dana 30 in the front if that sounds righ. my XJ is a 93 5spd. and what kinda diffreance it will make? thanks
 
regearing compensates for the larger diameter of larger tires. Normally, the rear end gear ratio is between 3.07 and 3.73 for a 4.0L engine and 4.10 for the little 2.5L four banger. what this means is that for every(3.55 ratio) 3.55 turns of the driveline, your wheels turn once. Now when you have a larger tire you need to slow down how many times it turns in relation to the driveline. This is done with a regearing of the differential and going to a numerically higher ratio. For 31-32"(for a XJ with a 4.0L) Dia tires one would normally want 4.10s. Now for every 4.10 turns of the driveline, the tires will turn once.

Try doing a search on "gear ratios", "regearing" and "tire sizes and gear". You'll be amazed at how much info is out there, since the is a very common question.
 
its not even lifted....just doing the leg work. because in a week ill be ordering my kit and tires.
 
buy another car to drive... I have done everything I can think of and after everything is said and done, I get 10 MPG... The civic gets 26+ at 240 RWHP.. vroom vroom
 
my double cardan joint started squeking so i took of my front driveshaft and i get supper better mpg. i was gettin 10 now im like 14-15 (probably i havent checked for sure) lol.... but im gettin it rebuilt so it will be back on here soon and back i go to 10 mpg haha
 
estimated of course. 80bhp = 240 hp at the rw, duhhhhh.
 
even better is his civic making the mazda power vroom vroom sound
 
the K&N air filter along with a throttle body spacer will help. i prefer the hesco spacer. these things can decrease the mileage as well, but i know on my 01 DD they boosted bottom end so i'm not revving it as much to get up to speed and get better mileage. just did the mileage check on my first freeway drive. went 130 miles and took 5.5 gallons to fill it up. had cruise control on the whole trip set at 70mph. around town at mostly 25mph i get between 16 and 17mpg. would be happier if the around town mileage was a couple higher.
 
Make sure you lift the rear higher than the front. That way your rig is always going downhill and saving fuel by coasting more. :confused1
 
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