Miles Per Gallon Loss?

[Xale]

hey, I am looking into buying a Honda CRX. I recently found a Manual 1991 Honda CRX HF, with 193k miles on it. The one thing that I am not sure about buying it for: the owner says it gets 25mpg. I thought that was horrible considering what they got new. I can expect the mpg to go down some, but I really didn't expect it to be that low. Am I wrong or is this car not worth buying?

[clantz86]

Could be a couple things..

-Perhaps he likes to burn the crap out of the car? That could cause low MPG, but if that is the case, it's not worth buying :P

-The car may just need a good tune up, a little TLC perhaps

-Check the spark plugs...if there's a problem with the engine, you might find it here. He shouldn't have any problems with doing this, and if he does, he's obviously hiding something. Exhaust might be restricted somewhere, or the air filter could be clogged also. (I noticed my mpg's going down, and decided to check my air filter...problem solved)

-If it's an HF, you might want to consider an engine swap anyway

[Xale]

Thanks. And yeah, this would be my first car with a limited budget, so I wouldn't be able to do an engine swap right away. I'll talk to him about the spark plugs, and see if I can look at it again.

[skotman]

worst any crx i've owned has ever gotten is about 30mpg.

i've noticed that my gas milage goes down slowly over time. lately i've been averaging 33mpg which is horrible considering that it got 37mpg 2 years ago and i've done all sorts of improvements, always keep up with oil, i've changed the plugs, wires, cap and rotor, timing belt, broke the distributor and changed it, etc etc etc. the only way to bring it back up again seems to be to burn through a tank and a half of gas in a day, like driving from here (picayune, MS) to atlanta, GA. any time i make a trip like that i get 42mpg. a whopping 9mpg improvement by doing nothing but driving. is this telling me that i've got crap somewhere in my fuel system? i've run fuel cleaner of all types through it and i get no improvement, again, unless i burn through a whole tank of gas in a day.

i'm wondering... is my throttle sticking to where i'm constantly leaking gas into the cylinders after the car is off, at least for a short time? i do know that my car will not start right after i shut it off. i've got to wait 10 - 20 minutes, but haven't been able to figure out what's causing this.

[livinincalifornia]

the HF should get 40-50 if it's in excellent running condition, it might take allitle work and some knowledge but you could probably get it there with a small amount of cash, unless the engine is shot to hell in which case you would want to put a new B7 in there which is also cheap, but requires <b>some</b> knowledge and tools.

[cpolaris502]

my mileage has been acting really strange lately. Ok, i bought the car back in december, the first tank of gas i put through in it i was drivng it really hard and seeing what it can do, redlining alot and what not. - I got 29 mpg. After that it has been bouncing all around, the worst mileage i got was 19MPG! Then i got 25 after that. Weird thing is now im halfway through a tank of gas and i have 150 miles on it, when usually i will have about 100 on a half tank. I dont get it. i been driving it prety consistent too.

I need to do a tuneup though, what kinda of things should i check/replace?

[CRXperiment]

To tune up you should change:
Air Filter (If dirty)
Distributor Cap (If lots of oxidation residue)
Rotor (same as distributor)
Spark Plug wires (If in bad shape, torn, or peeling paint, take them out and inspect the actual metal wires)
Spark plugs (easy to do and woudlnt hurt to change anyway)
Change PCV valve? (may help with gas mileage and aid oil consumption)
Clean EACV
Possibly change O2 sensor if old
Change oil to nothing higher than 10W30 (5W30 preferred)
Am i forgetting something?
PS make sure to inspect your plugs after taking them out...
GL

[FrodoGT]

Well on a tune-up I would drain and change the trans fluid. Check clutch adjustment (a slipping clutch makes bad mileage too). And inspect your cv axles and brakes...if the cv's are binding or brakes are dragging your just eating up mileage and part wear.

[turtlecrxsi]

Originally Posted by CRXperiment

To tune up you should change:
Air Filter (If dirty)
Distributor Cap (If lots of oxidation residue)
Rotor (same as distributor)
Spark Plug wires (If in bad shape, torn, or peeling paint, take them out and inspect the actual metal wires)
Spark plugs (easy to do and woudlnt hurt to change anyway)
Change PCV valve? (may help with gas mileage and aid oil consumption)
Clean EACV
Possibly change O2 sensor if old
Change oil to nothing higher than 10W30 (5W30 preferred)
Am i forgetting something?
PS make sure to inspect your plugs after taking them out...
GL

This is all good... see my response to your other thread. Also, poor tire inflation can give shitty gas mileage. True story.

Just thought of something, car could have big heavy rims which would give shitty gas mileage to a car that is slow and may have been riced/raced.

Or the car could have an engine swap already or all of the above, but I've even heard of b-series getting 30mpg, unless turboed.

GL

[FrodoGT]

My B gets 27mpg, and im on it at almost every opportunity (not screaming to 8k mind you), I also have shitty wiring,and right now Im throwing 2 trouble codes because Im a lazy ass and dont want to go pull a knock sensor...

[bambam89lx]

Originally Posted by skotman

worst any crx i've owned has ever gotten is about 30mpg.

i'm wondering... is my throttle sticking to where i'm constantly leaking gas into the cylinders after the car is off, at least for a short time? i do know that my car will not start right after i shut it off. i've got to wait 10 - 20 minutes, but haven't been able to figure out what's causing this.

nope. After the car is off, no more fuel is injected, regardless if the throttle is open or not. And the not starting problem is most likely a main relay going bad. that's exactly what they do when they start to go bad. It may also be your coil or ignitor. I've never seen it be anything else.

[FrodoGT]

Fuel injection is just that...a current is sent to thge injector telling them to open and release the fuel into the intake...when the car is off, the injectors close, the fuel pump shuts off and no more fuel is released...

[cpolaris502]

Originally Posted by CRXperiment

To tune up you should change:
Air Filter (If dirty)
Distributor Cap (If lots of oxidation residue)
Rotor (same as distributor)
Spark Plug wires (If in bad shape, torn, or peeling paint, take them out and inspect the actual metal wires)
Spark plugs (easy to do and woudlnt hurt to change anyway)
Change PCV valve? (may help with gas mileage and aid oil consumption)
Clean EACV
Possibly change O2 sensor if old
Change oil to nothing higher than 10W30 (5W30 preferred)
Am i forgetting something?
PS make sure to inspect your plugs after taking them out...
GL

Which of these thing in this list wouldi see the biggest MPG increase from doing.

Changed tranny fluid today and spark plugs, cleaned out the eacv with carb cleaner and air compressor, my air filter is good and so is the engine oil.

[Concept Tuning]

Tire pressure is a big one. I can tell when my tire pressure starts to drop cause I get piss poor gas mileage. Another thing I have noticed is that I get better gas mileage on "name brand" gas. Those cheap gas stations can have additives. Might want to check and see if they are adding more ethanol to their mixture. That would give you a drop in MPG since it takes twice as much alcohol to make the same power as gasoline.

[FrodoGT]

Tire pressure is definately big, for 25c you can get at least 5mpg if your tires are improperly inflated. Also, alignment is big as well, and itll wear your tires out at the same time..double whammy!