i tried searching for this already, but I couldnt see anyone else with this problem

I have a brand new 2.0l protege5. I noticed good MPG for about the first 400km of my new engine, but now I get complete crap. I am lucky if I hit 22MPG, even with 30% highway driving.

Anyone else have this. I am only have 1300km's on it so I doubt it is the air filter, PCV or tire inflation?

I dont even drive the engine that hard either. Lucky if she ever gets above 4000rpm during the breakin period.

 

I average about 23MPG but I added the CAI & the Bosal cat back. Didnt really expect a big gain in MPG but I didnt really expect a big loss. I think before I added those I was getting about 24MPG which isnt the greatest. Seems like they stated like 28-31MPG or so. I have the auto which drops a little. Either way, it seems like Im getting a few MPG less than I would expect (and yes, it was higher when I first got it). So, I dont really know what would do it. It does sound like your MPG is a little worse than mine too. I do very little Highway driving so that will make up for a little of the loss.

 

I'm in the same boat. I average in the low 20s. Granted, I do lean into it every once in a while. But even on the tanks where I drive conservatively, it still pulls low 20s. I've checked tire pressure, too. Any ideas?

 

Yes, it has been posted before. First tank 400 miles, 2nd tank 375 miles, 3rd tank 350 miles. It seems the cheaper the gas the better. With Texaco and Mobil I get average of 300-315 miles. With cheap Costco and Racetrack I get average of 335-350. If our tanks hold 13 gallons? then that is 26.9 miles per gallon. I guess right in the middle for an automatic. So I guess I can quit my bithcin.

 

I have put about 3 tanks of gas in so far. I never let it get completely empty but I have yet to reach the 300 mark; I get anywhere from 260-280. I do drive hard but I am never at WOT. I have done no mods so far and I drive a manual. Something doesn't feel right about that. Thanks

Dustin

 

the first three tanks in my car were pretty much light driving. Tank one was around the city and was in the mid 20's, tank 2 was pretty much all highway and was at about 29 same for tank 3. The fourth one was pretty heavy city driving and I did not check.

(of course this uses the highly accurate "number of miles on the trip counter/how many galons went in when the fuel pump cut off at the station" method)

I guess I will need to take alook again and see what this last one is going to be...

 

I thought our tanks in the P5 hold 14.5 gallons. Well i know for sure that it holds 55 gallons, for us canucks. Dont know though what this 100km/9.7l bullcrap is all about, so i always convert to MPG.

 

I am getting 8.5 liters per 100 km or roughly 27 mpg with 87 gas and redlining it on regular basis. I usually drive 80-85 mph on highway.
Highway/city is about 70/30% with frequent traffic jams.
I shift to higher gear below 3000 rpm(unless I am redlining it) and try to cruise around town at below 3000 rpm paying attention to traffic lights.
when I had few highway only trips, I was getting 31 mpg...
car has now 7000 miles.
Terrain is flat in Toronto...could be reason as well
Pushing it off the line is eating more fuel, even if its not redlined.

 

geez, i feel like i got the best engine now.

i thought that i was getting bad milage by only getting 29-31 mpg per fill-up, and if i drive moderately, i can even sqeeze 32-33 mpg. but then when i find that i get on it more in a tank, i will only get about 26-28 mpg. i don't know what you guys are doing to get such low milage, but i do know i am doing much better. maybe we get better gas in new york state. and all this relates to filling up when the low fuel light comes on, and i have at least 325-350 miles on the clock.

on a side note, my wife's civic lx gets ON AVERAGE 34-37 mpg. she can AVERAGE 325-370 miles per tank, with an 11 gallon tank.

 

Yeah, fuel economy was a bit a dissappointment for me too. We traded in a Saturn that was still getting 40mpg on the highway with 180,000 miles on the ticker.

I think a lot of the mileage problem is due to gearing. With the cruise set at 75, I'm seeing about 3200 RPM. On the Saturn, it was only at about 2800. My Grand Prix weighs about 800lbs more and has almost two and half times the HP and Torque, that even gets better gas mileage on the freeway. The GP sees about 2200 RPM cruising at 75.

Set the cruise at 55 on the Protege, I'd imagine you'll see a sustantial increase in fuel economy.

 

gotta love how low the RPM get on those V6 GMs. My Chevy with the 3.1L V6 still gets 30mpg on the highway at 150k miles on the odo... too bad that the other parts of the car could not be trusted on long trips anymore.

 

i still don't know what you guys are doing to get such low milage! this morning, my fuel gauge is telling me i have 1/4 tank left, and my odo. is reading 362 miles!

 

TheMAN:

I'd say you are getting good milage also, considering the way you drive. I'm sure if I drove that way, my milage would be similar. I also use 93 octane gas and have a K&N drop in filter. I think my engine is still green too, with only 7800 miles.

By the way, I was driving around at luch break and my gas light came on. I looked at my odometer and it read 380 miles.

 

What's the procedure to reset the ECU?

 

I believe is to disconnect the battery and press the brake pedal for a few sec to drain out the remaining juice.

Would be nice if there was a fuse to the ECU so that we can just unplug the fuse for resetting.