Hey,
Ive got a 91 automatic with a rebuilt 3.slow.Im only getting 13 mpg.Ive replaced the fuel filter,plugs,wires,distributor,and injectors.I know these vehicles are not known to be the greatest on gas but 13 mpg is ridiculous.My tires are 265/70/17s(32x10.50) and I really dont think they would be causing this.I do have the known code 52 popping up that is common with the rebuild,which results in loss of power.Anybody have any ideas?

 

what gears do you have with 32s and an auto?

i am running the similar sized tires, with 4.56 gears. i am getting 14mpg on average.

 

Stock gears,I have been reading through some threads and am noticing Im not the only one.I read where one guy put a high flow cat on with a k&n filter and a bigger exaust and he said hes getting arond 300 miles to a tank with 31 inch tires.Ive been wanting to put a k&n filter and new cat on...

 

what "stock" gears.. there are several there is a vin tag on the body door jam. in the lower right it will say Gxx4 somewhere.. what does the xx say?

i have a brand new cat (OEM replacement not free flowing) and air filter... didnt help much. lol i went from 13 to 14 when going from 4.10s to 4.56s

 

What ever the factory installed..I wasnt aware that these model runners(3.0) where available with different gears.I just thought they all where installed with the same gearing off the line.Learn somthing new everyday..lol.The numbers are G254,they followed after A/T which Im guessing means automatic tran...Im pretty sure I could use some sort of new cat,my exaust isnt sounding as throaty as it did,seems as if there is more exaust noise coming from underneath the floor board than the muffler...exaust system is leak free

 

G254 is 4.56 gears...


yes, you can find 4.10, 4.30, 4.56, 4.88 all "stock" depending on the year motor and tranny

 

My 95 automatic 3.slow Runner came with 4.88 gears. At the time that i had just 31's and no armor + add ons. I did have a S&B cold air intake, performance plugs (like 4 prong plugs instead of just regular plugs), and nitrogen in my tires which are supposed to help with mpg (by just barely) in hotter whether. It only cost me like 20 bucks to fill nitrogen. I also had a air filter thing in my intake called a Tornado thats supposed to spiral the air in your engine increasing mpg (i dont think it did much) but i got around 15 mg when i drove conservatively

 

I havnt put to much thought or work into the gearing.The tran seems to work well them tires so all I dd was change the filter and oil(with a splash of seafoam) in the tranny,lot smoother shifting.If I had any bigger of tire and lift I would change the gears...

 

O2 sensors can fail without throwing a code. 19 years is a long time if you haven't changed it.