Really Poor Fuel Economy

sinhron · Post by **sinhron** » October 5th, 2005, 12:11 am

Hello there people.
I've been experiencing really bad fuel economy with my MX-3 V6 K8.
I mean like , I put in $20 gas, and I can drive about 150 kms in the city!?
Is that normal for this type of cars, is it the fuel prices that are fooling me, or is there something wrong with my car that I can do about ?

I can't get more than 300 and some kilometers on a full tank in city driving, no matter what kind of gas I put in.
Any input would be appreciated.
Thanks

neutral · Post by **neutral** » October 5th, 2005, 6:41 am

Assuming the engine has been been given a standard tune-up already, i.e. new plugs, disty cap & rotor, sparkplug ignition wires (if not replaced wothin last 80km), AIR filter, then your O2 sensors might be the culprit - esp. if they haven't been replaced within the last 160km. When the O2 sensors wear out, it means your engine is constantly "guessing" at the accuracy of O2 output in the exhaust stream and this can cause a severe drop in fuel mileage.

mitmaks · Post by **mitmaks** » October 5th, 2005, 1:50 pm

230mpg on tank of gas in gs

Chiggles · Post by **Chiggles** » October 5th, 2005, 5:28 pm

sinhron - that sounds pretty normal to me. In my case, a full tank of city driving will last me about 320kms. The absolute MOST I've gotten out of tank by running it dry til it sputtered and died of thirst was 412kms but generally, from the point the "low fuel" light stays on brightly lit to the point where it's filled to the brim and starts overflowing at the opening, I get about 39L of gas in the tank and that lasts me like I said about 320kms. I think the recent jump in gas prices is just messing with you. I just gassed up this past Friday and paid $40.

Mind you though, I don't think the O2 sensors on my car have ever been changed, so if my mileage is less than normal for a V6 running an ATX, somebody let me know and I'll get my O2 sensors changed right away. Right now, I'm sitting at 122,176 kms. Am I due up for a change???

Legato626 · Post by **Legato626** » October 5th, 2005, 7:09 pm

i got 300mpg on highway =) but 200-230 that sounds right for intown driving. Thats what i get in my GS.

schuttie2002 · Post by **schuttie2002** » October 5th, 2005, 7:30 pm

you guys seem to get really shitty gas mileage in my book. With the old K8 i got 28-30 mpg all the time and with the new DE i still get like 27-29 all the time. So I always get over 300 miles to a tank which is 500km's right

sinhron · Post by **sinhron** » October 5th, 2005, 8:19 pm

I wish I could get 500 kms per gas tank. If I keep my feet on the gas, I would hardly get 250

Thanks for the input though, I will try and change the o2 sensor, to help improve the fuel economy.

mitmaks · Post by **mitmaks** » October 6th, 2005, 12:02 pm

schuttie2002 wrote:you guys seem to get really shitty gas mileage in my book. With the old K8 i got 28-30 mpg all the time and with the new DE i still get like 27-29 all the time. So I always get over 300 miles to a tank which is 500km's right

i dont see how thats possible, unless you screwed up with fuel supply

glow · Post by **glow** » October 7th, 2005, 10:57 am

I get like 300km on a full tank if I'm lucky, but like someone else said, I don't think I have my O2 sensor replaced, and I think I'm due for a tuneup

mxmaz · Post by **mxmaz** » October 7th, 2005, 11:08 am

I ran my car dry once. It was sputtering and cutting out on my way to the gas station. I got 49.5L in the 50L tank, that how dry it was. The car got 450km on that tank and both of my o2 sensors need raplacing.

Nd4SpdSe · Post by **Nd4SpdSe** » October 7th, 2005, 11:11 am

I never brok 400km with my k8 ever, i was averaging 350km a tank, and the engien only has 109km's on it when i bought it. Coming back from Ottawa in spring, i got 510km/s on about 40L

Big D · Post by **Big D** » October 7th, 2005, 12:34 pm

strange... I fill my tank up when the light comes on (takes about 39L) so I have about a 10-11L supply still in it, and I get 500KM on that 40L, so with the extra 10 I bet I could push 600 but I dont want to try. And its on a K8...just my .02

Nd4SpdSe · Post by **Nd4SpdSe** » October 7th, 2005, 12:36 pm

I have never passed the 40l mark, the most I've put in was like 39-something

Juans_93_MX3 · Post by **Juans_93_MX3** » October 7th, 2005, 9:57 pm

How much would you guys say O2 sensors cost?

glow · Post by **glow** » October 7th, 2005, 10:21 pm

wow you guys are getting some pretty sweet mileage out of your mx3's. hopefully a tune up will help mine, and i can at least get 350-400 kms out of a tank