BAZ

So my '90 Si is completely stock and has 162k on the motor. Its getting what I think is very poor gas mileage (250ish miles per tank. I'm not really sure where to start at addressing this problem. It runs fine. What is everyone else getting out of their Si?

brownman

i get 250 per tank too stock motor w/ 152k

JAYB90

well if you dog it everywhere you go that could be somthing, and you get like 25% less gas mialiage when your under half a tank. i got 300 to a tank on my d15

BAZ

Well, I really dont beat on this car at all. I actually take it really easy. I've heard of people getting upper thirties on the same motor/tranny.

sh!ft

before, when i had my b2, i got 45+ mpg but now with the z6 i can get lucky if i can get 100 outta half a tank.....mabey cause my o2 isnt hooked up or im running open header

robs1stcrx

give it a tune up or maybe cat is clogged

JAYB90

yeah i made a typo, i made 350 on my 90 ef sedan d15. and 300 when i dogged it a lot. i got 31 mpg. and the si's should get 28 i believe. i dunno use search, i know for a fact theres a thread identicle to this one with some real answers....

crx(gator)

how many gallons does the car take? you cant say xxx miles per tank...give us a proper MPG number...

SceneMotorsport

I dont have a Si, but i just bought a DX, stock motor right now and im easily getting over 300 a tank. I wonder how much the MPGs differ between DX and Si.

digitally_remastered

i was getting 320+ on a tank with my old d15b2 bottom end and y7 head on a mpfi converted std hatch i used to own. and this was also with a 4 speed trans. ran this combo for 4 years. probably the best gas millage i ever got with any car. even with my dpfi sedan i got now i can barely manage to get 250 out of a tank....

first thing i would tell you to do is plugs, cap and rotor, wires, and check your timing. then see about getting some newer injectors or getting yours cleaned. also do a compression test. just general maintenance will do wonders.

goodluck!!

90 DX Driver

get a stock exhaust. if you have something that is way too open youll lose power and use a bit more gas to get the car going..

Mine is only getting 250 a tank (Tank is about 10 gallons) so its 25mpg.

I have a Rice cannon however....My buddy had the same problem..swapped to 2inch-2.5inch pipe back with turbo muffler and dual tip and wala!!! 30mpg+

1fastefhatch

My bro has a 89 si and it has intake header exhuast and a msd external coil setup and he gets 365ish but he comutes like 120 miles every day in it it has like 190,000 and has never been rebuilt and i have a 90 with the same amount of miles with intake exhuast and a test pipe and get 310 if im lucky but i ussually just drive in town

BAZ

Thanks for the responses guys. I'll check the timing and do the plugs, wires, and cap/rotor. I was planning on doing it anyway. I actually have a new OEM honda Si catback so like I said, the car is completely stock. Anyway, it seems like its closer to normal MPG than expected. If anyone has any more input let me know. I would like to be getting 30+ MPG but if 25-28 is normal, then so be it.