Indeed, I do notice slightly a better mpg during late summer than in winter, but the difference is very slight, almost negligible- around 1mpg difference.

oh i guess the A/C factor comes in...

Jacek writes:

I'm not the original poster but your advice is insulting. If you reread the very first post, you will find the poster used to get 30mpg in old Corolla and is getting 24mpg in the new one WITH THE SAME DRIVING STYLE.

My corolla also has suboptimal MPG REGARDLESS of driving style. I get 27mpg in city with regular driving and 28mpg with super duper granny driving (keeping RPM under 2000). I also get disapointing 30-31mpg on hwy. So, I'm very sympathetic to the original poster's cause as I went through the same disappointment. The car now has 30000 miles and it's the same, so don't count on improving. BTW, I keep tires inflated to 36 psi and observe all precausions to save fuel.

Clearly, some corollas are not as efficient as others and it would be nice to discover the root cause. Blaiming on the driver is contraproductive.

Thanks for the support Jacek. I pretty clearly stated that my driving habits haven't changed since I had my previous vehicle, which I was getting 30 mpg with. Since I started this thread, I've been checking everything I can on the vehicle. The air filter is clean. One of the tires was strongly underinflated, and I hoped that would be the root of the problem - after making sure all tires were at 30 psi (the recommended inflation, and what I kept the tires on my previous vehicle at), the mileage picked up a little. Its now more like 26.6 mpg, still not nearly what it should be. If anything, '05 Corollas are supposed to get better mileage than '95 ones (like my old vehicle).

Interesting to read that this is a known problem with some '05 Corollas - I wish I'd known that before I bought one! If I'm stuck with one of these, is there any known fix?

I've been talking to the service department of the dealership - complete stone wall with these people. The mechanic there claims the only thing internally that could throw off the mileage would be the emissions system, and that that would automatically set off the "check engine" light. The only other thing they held out was that they could run a diagnostic (at my expense unless a warranty-covered problem turned up.) I've called Toyota Warranty service - they suggested that the vehicle may have been driven wrong during the "break in" period and that, if possible, the dealership mechanic might be able to erase out the stored info on the car's computer, and I could then break it in again. Does that sound like a good solution?

Its a nice car and I got a really good price on it (a few thousand below MSRP, which also now makes me suspicious), but one of the reasons I chose a Corolla was for the mileage, and it sucks to see that's not up to snuff.

Peter

I've called Toyota Warranty service - they suggested that the vehicle may have been driven wrong during the "break in" period and that, if possible, the dealership mechanic might be able to erase out the stored info on the car's computer, and I could then break it in again. Does that sound like a good solution?

Its a nice car and I got a really good price on it (a few thousand below MSRP, which also now makes me suspicious), but one of the reasons I chose a Corolla was for the mileage, and it sucks to see that's not up to snuff.

Peter

It is true that the ECU learns how you drive it and adjust the tranny shift points and possibly other thing to suit your driving style, but it doesn't take long to relearn a change, so the claim that the car needs to be "broken in" again makes no sense to me. I reset ECU/TCU in my subaru a few times with no impact on MPG. Didn't try in toyota though.

This brings another issue whether improper brake in (in mechanical sense) in the first hundreds of miles can permanently harm the engine in a subtle way and affect MPG.

When I took a delivery of my "brand new" corolla, it had 500 miles on it as it was a dealer exchange. I was furious about it but accepted after all as it had hard to find options. It was probably abused with high speed hwy driving.

I've called Toyota Warranty service - they suggested that the vehicle may have been driven wrong during the "break in" period and that, if possible, the dealership mechanic might be able to erase out the stored info on the car's computer, and I could then break it in again. Does that sound like a good solution?

Its a nice car and I got a really good price on it (a few thousand below MSRP, which also now makes me suspicious), but one of the reasons I chose a Corolla was for the mileage, and it sucks to see that's not up to snuff.

Peter

It is true that the ECU learns how you drive it and adjust the tranny shift points and possibly other thing to suit your driving style, but it doesn't take long to relearn a change, so the claim that the car needs to be "broken in" again makes no sense to me. I reset ECU/TCU in my subaru a few times with no impact on MPG. Didn't try in toyota though.

This brings another issue whether improper brake in (in mechanical sense) in the first hundreds of miles can permanently harm the engine in a subtle way and affect MPG.

When I took a delivery of my "brand new" corolla, it had 500 miles on it as it was a dealer exchange. I was furious about it but accepted after all as it had hard to find options. It was probably abused with high speed hwy driving.

I often wonder the same about my Mazda3. The salesman had to bring the car up from another dealership 60 miles away.. and it was driven by his (salesman's) son. Why it wasn't put on a truck, I don't know.

Anyway, the transmission (auto) on the car just doesn't want to behave on a consistent basis. It feels very sloppy.. does a lot of hunting on upshifts. Sometimes I think it could be due to the punk kid running the hell out of the car on it's first few miles. I have reset the ECU a few times, and it helps, but it shortly reverts back to misbehaving.

It's nothing detrimental that I can prove wrong... just a massive amount of complaining on my part. it does make the drive less enjoyable, though.

And that's one of many reasons why I will never buy an automatic again, if I can help it.

I was somewhat unforgiving to my corolla when I first bought it brand new with 3 miles on it. Although, 90 percent of the time during the first 1000 miles I let the car shift under 3000 rpm. As for the rest 10%, I went up to 5000 at the most.

All the problems (especially low MPG) with the newer Corollas makes me less likely to purchase one in the future. I think I will stick with my 7th generation ones that get almost 30 MPG consistently. I don't want to spend lots of $$$ on a new car that does not even get the MPG that I am getting now with a car that is paid for.

I can't agree more, bikeman. My next car would probably something other than toyota.

I am hoping with the technological advances and also the ever increasing cost of fuel that something driveable will come along soon that is also affordable. I plan on saving my pennies until my car will no longer be viable as a continuing source of transportation for me. I am seriously considering a Hybrid or electric vehicle that is not 100% dependent on fossilized fuel for propulsion. I have nothing against Toyota, other than the poor fuel consumption and the looks of the newer cars, as well as the prices.

I am hoping with the technological advances and also the ever increasing cost of fuel that something driveable will come along soon that is also affordable. I plan on saving my pennies until my car will no longer be viable as a continuing source of transportation for me. I am seriously considering a Hybrid or electric vehicle that is not 100% dependent on fossilized fuel for propulsion. I have nothing against Toyota, other than the poor fuel consumption and the looks of the newer cars, as well as the prices.

LOL, the best hybrids are made by Toyota. My next car has to be a plug-in Hybrid. Commuting on electric power, sweet.

BTW, I wasted some time on BITOG again. Found something interesting. One guy boasted geting 40+ MPG in Corolla while driving at moderately high altitude: 4700 feet and higher.

Interesting, I have disappointing MPG and drive exlusively at 0-1000 feet.

Any more inputs on the altitude thing?

http://theoildrop.server101.com/cgi/ultima...t=002831#000000

I am hoping with the technological advances and also the ever increasing cost of fuel that something driveable will come along soon that is also affordable. I plan on saving my pennies until my car will no longer be viable as a continuing source of transportation for me. I am seriously considering a Hybrid or electric vehicle that is not 100% dependent on fossilized fuel for propulsion. I have nothing against Toyota, other than the poor fuel consumption and the looks of the newer cars, as well as the prices.

LOL, the best hybrids are made by Toyota. My next car has to be a plug-in Hybrid. Commuting on electric power, sweet.

BTW, I wasted some time on BITOG again. Found something interesting. One guy boasted geting 40+ MPG in Corolla while driving at moderately high altitude: 4700 feet and higher.

Interesting, I have disappointing MPG and drive exlusively at 0-1000 feet.

Any more inputs on the altitude thing?

http://theoildrop.server101.com/cgi/ultima...t=002831#000000

Filled up the other day, got 32MPG (city driving) - this is pretty much what I always get, I use 89 octane most of the time. Mine's a 01 LE.

I am still looking for a method to simulate high altitude for my car. That way I can get better mileage. I drive it mostly at or around sea level and with mostly highway miles and a light foot I can get 30 MPG.

I am still looking for a method to simulate high altitude for my car. That way I can get better mileage. I drive it mostly at or around sea level and with mostly highway miles and a light foot I can get 30 MPG.

Easy way is to take a road trip to CO . The higher altitude also relaxes the octane requirement for gas engines - many can use 85 octane just fine. Also altitude plays a big role in power - your car will make less power at higher altitude, forced induction engines (turbos, superchargers) really start to shine here. Same with turbo-diesel powerplants - they can tow loads at high or low altitude with little problem. I doubt it would have much bearing on overall MPG - since most computer-controlled engines can adjust spark timing and air-fuel ratio to compensate for changes in barometric pressure (makes the effect of altitude smaller).

 

I was thinking more of bringing the higher altitude of CO to my area that I drive, since someone has commented that they got much higher MPG at the higher altitude. I don't plan on moving and I could always use better MPG.

Only if you find a way to bend the laws of physics. You can easily trick the ECM with resistor tricks (not recommended, potential for engine damage for small increase to fuel economy) - but you cannot easily reduce the amount of drag on you car to mimic driving at 4000 or 5000 feet vs sealevel. The aero drag on the car in CO is less than what you will every see at sealevel - car doesn't have to work quite as hard to move around, a good thing, since the higher altitude also sucks down your power.

 

That was more of the idea that I had in mind. Altering the controls on my car into believing it was at a higher altitude. I wonder if anyone has ever done that??

That was more of the idea that I had in mind. Altering the controls on my car into believing it was at a higher altitude. I wonder if anyone has ever done that??

They've done the opposite - making the engine think it had more air to work with - you see them on eBay all the time. So called resistor scam - since the car will be running the wrong air/fuel mix. Running the other way is not as popular - since you will be telling the car that you have less air to work with = less power. Might give you better MPG, but the trade off would be constantly tripping the knock sensor (less fuel to help cool intake temps) - which will result in more fuel and less spark advance = items that work against fuel economy.

 

Big thing would be the aero advantage at higher altitudes (14.7PSI at sealevel, 12.2 - 12.8PSI at 4000 or 5000 feet). Doesn't sound like much, but a significant amount that will affect your numbers. Something that cannot be replicated with any electronics on the car.

I was thinking more of bringing the higher altitude of CO to my area that I drive, since someone has commented that they got much higher MPG at the higher altitude. I don't plan on moving and I could always use better MPG.

Only if you find a way to bend the laws of physics. You can easily trick the ECM with resistor tricks (not recommended, potential for engine damage for small increase to fuel economy) - but you cannot easily reduce the amount of drag on you car to mimic driving at 4000 or 5000 feet vs sealevel. The aero drag on the car in CO is less than what you will every see at sealevel - car doesn't have to work quite as hard to move around, a good thing, since the higher altitude also sucks down your power.

 

That was more of the idea that I had in mind. Altering the controls on my car into believing it was at a higher altitude. I wonder if anyone has ever done that??

Bad idea.

I posted the link merely to gather input whether the higher altitude observation has any validity.

Bikeman, don't you spend too much time on this board?

I was thinking more of bringing the higher altitude of CO to my area that I drive, since someone has commented that they got much higher MPG at the higher altitude. I don't plan on moving and I could always use better MPG.

Only if you find a way to bend the laws of physics. You can easily trick the ECM with resistor tricks (not recommended, potential for engine damage for small increase to fuel economy) - but you cannot easily reduce the amount of drag on you car to mimic driving at 4000 or 5000 feet vs sealevel. The aero drag on the car in CO is less than what you will every see at sealevel - car doesn't have to work quite as hard to move around, a good thing, since the higher altitude also sucks down your power.

 

That was more of the idea that I had in mind. Altering the controls on my car into believing it was at a higher altitude. I wonder if anyone has ever done that??

Bad idea.

I posted the link merely to gather input whether the higher altitude observation has any validity.

Bikeman, don't you spend too much time on this board?

Ok, I won't alter my engine to think it is at a higher altitude or purchase one of those chips.

I only spend an hour a day on this board - ok, maybe two. Are you trying to get rid of me?

Are you trying to get rid of me?

I hate to sound unfriendly, but are you familiar with the concept of hijacking a thread?