On my 94gsr w/ 120k miles, I'm usually hitting about 220-225 and thats with the empty gas light coming on. I done the full tune-up, all with factory Acura parts. Replaced dis. cap&rotor, spark plugs, spark plug wires, fuel filter and air filter. Not much of a improvement in terms of gas mileage. I checked my spark plug and the tip according to the repair manual look fine, so that indicates the car is running properly. I had the timing checked and that was fine too, so I am lost as to why I'm getting such "poor?" mileage. Also, the tire pressure are correct and alignment is straight and fine.

The o2 sensor should be fine also since I don't get a check engine light or smell gas from the tip of the exhaust. I'm lost as to what may be the problem?

Only thing I haven't done is the valve adjustment and change the pcv valve, would this make any difference? I was told that at most the valve adjustment would just make the car "quieter and drive a little smoother", not sure about improving gas mileage. Will changing the pcv valve also make a difference?

 

valve adjustment will help you with gas (in some ways and with my own experience).

I get about 220 per tank with my turbo/fully built setup and that's brand new everything (fuel, oil, water pumps etc.)and I have bigger injectors from RC so..

Before valve adjustment I was getting less than 18 and now I'm back @ 22~23 after Val Adj. Don't know, I'm not the expert but this is all I can tell you.

 

Anyone else? My car is bone stock too. I don't redline my car nor drive like a speed racing. I shift at around 4k rpm.


[Modified by mickey513, 2:41 AM 2/1/2003]

 

I just had my valves redone and I am still seeing less than great mileage.

 

Do a basic tune up: fuel filter, air filter, spark plugs and wires.

Check tire tread, pressure, etc.

Good luck.

 

Anyone else?

 

how bout lots of carbon buildup. I am not mechanic, but my theory on carbon build up is that it can prevent the valves from properly sealing during combustion. But what do i know, i also believe the same carbon build up raised my compression .000001.


here is my exhaust side with ~150K miles. It still is like this, don't now the proper way to clean it besides getting the head port and polished. I got around 240-250 before replacing dist. cap, rotor, plugs and wires; oh yeah, and damn igition coil (failed). After the unplanned tune up, i am getting about 260-270 before idiot light comes on. Finally got passed 300 miles on a tank.

 

Go to a shop and have them professionally clean your fuel system. It should cost less than $100. They disconnect the fuel pump and idle your car off this special cleaner 'til it runs out. It's more efficient than that stuff you pour into your gas tank.

Also, the fact that it's winter doesn't help. In the summer you should be seeing about 40-50 more miles per tank.

HTH

edit: that cleaning system i mentioned should clear all that carbon buildup out of your CC also


[Modified by ingrate, 11:18 PM 1/31/2003]

 

try using a complete fuel injection system cleaner. i use stp complete fuel system cleaner every other oil change or so. i also used a product called RESTORE when i change my oil. it didnt really make a difference on my gsr because i still only have 78,000 miles, so i stopped using it, but it did wonders for my friends LS with 110,000 miles.


[Modified by turb0accrd, 7:19 AM 2/1/2003]


[Modified by turb0accrd, 7:20 AM 2/1/2003]

 

My car has 130K miles and I can get 350-370 miles out of 11 gallons or so, if it is strictly highway driving. The only time the gas light comes on before it hits 300 if the entire tank was 100% city driving.

Also why is economy worse in winter? Shouldn't it be worse in summer (for the general population) due to using the A/C and the fact that the intake air is less dense and more humid?

 

oh, whoops, didn't account for A/C. I don't use it that often anyway. I can't really explain why, but i consistently get 27-28 mpg city driving in the summer, as opposed to 24-25 city in the winter. I always hated chemistry anyway, maybe someone else could be more equipped to answer that. My guess is since the air is less dense in the summer, the ECU will compensate for it and lean out the fuel mixture a bit.

 

some suggestions: check the o2 sensor and replace if necessary and have your injectors cleaned at rc engineering.

 

to consider:
CHeck tire pressure, yours may be low.
most of your driving is city/local versus highway/freeway
lead foot driving... shifting at 4k doesnt mean you dont shift often or pull the car fast off the line
using lower octane petrol. 92+ typically allows your engine to run more efficiently.

just some thoughts in passing. cheers.