Toyota Prius Forum banner

1 - 20 of 26 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter · #1 ·
:( Hi my name is dan and I am havine a problem with my prius. I hope someone can help.
I was always averaging 47 to 49 miles per gallon. Until 2 days ago everything changed. I have the same driving pattern and direction to and from work but now I average 44 to 45 MPG and thats it. I have changed nothing. I call the dealer and they say they can not look at it unless a check engine light comes on or something drastic happens. Pls help.

Thank you,

Dan
 

·
Registered
Joined
·
1,560 Posts
flat tire?
 

·
Registered
Joined
·
3 Posts
Discussion Starter · #3 ·
no, not a flat tire. I think something is wrong with the computer chip or ?, The problem is they will not even look at it unless a light comes on stating engine problem or something like that"


Dan
 

·
Registered
Joined
·
370 Posts
melgish said:
flat tire?
Or maybe just an underinflated tire.

And Dan, if you could put your location info into your profile, we might be able to come up with a geographical reason.

Personally, I've experiencing the exact opposite mileage. Usually, I get 47 mpg driving to and from work. So far with 4 commutes this week, I'm getting 51. I'm looking forward to see what I get on the rest of the tank.


DGStan
 

·
Registered
Joined
·
6 Posts
I had / still have a similar problem, I have gotten 50 mpg out of a few tanks but lately it seams I'm only getting 42 mpg, and yes the dealer said they can't do anything unless the warning light comes on. They said it could be that the summer heat is taxing the AC more but I've always driven it with max cool setting, I don't know the answer.
 

·
Registered
Joined
·
6 Posts
I had / still have a similar problem, I have gotten 50 mpg out of a few tanks but lately it seams I'm only getting 42 mpg, and yes the dealer said they can't do anything unless the warning light comes on. They said it could be that the summer heat is taxing the AC more but I've always driven it with max cool setting, I don't know the answer.
 

·
Premium Member
Joined
·
888 Posts
Gasoline quality can vary from station to station, brand to brand, and even tank to tank. If you refilled your tank recently at a station other than one of your normal ones, or your station recently received a refill of gas, that new gas might have different fuel to additives properties. This will change how well it burns in your vehicle and subsequently will have an effect on your MPG.

A drop of 4mpg isn't particularly significant in the grand scheme of things. I'm inclined to believe it is either tire pressure as has been suggested already, or it is different fuel. I run 40/38 on mine and get about 47 mph. My mpg does vary from tank to tank. There is variability in the amount of fuel energy from tank to tank because of variances in the fuel that gets trucked into the station.

Don't waste your time with the dealer, obviously they are not going to be helpful (go find a different dealer for future service which is more sympathetic) and give the car a few more tanks of gas before you think something is technically wrong with the vehicle.
 

·
Registered
Joined
·
7,161 Posts
Even at max cool, I am sure the AC compressor runs slower when outdoor temps are cooler. There is a limit on how low AC is allowed to chill the air. This is even true with conventional AC, where the compressor has 2 speeds: off and on, and no cabin temperature sensing. The only thing sensed is to be sure the evaporator doesn't reach too low of a temperature.
 

·
Registered
Joined
·
582 Posts
low mpg

Cycle the parking brake a few times. Drive some distance in reverse, then firmly press the regular foot brake. Your shoes may be draggin'

DAs
 

·
Registered
Joined
·
117 Posts
Don't think that is a big enough change - for one partial tank to be too worried about. Could be as others have said such things as tire pressure, temperature, fuel btu value, wind conditions, temperature - or one I may have missed - wheel alignment. If it persists after two or three tanks, then go back to the dealer and lie. Tell them that the mileage has dropped AND the engine is running rough at times.
 

·
Registered
Joined
·
17 Posts
mine is low too

I do alot of driving have logged 20k in 4 months and for the last 10k have been only getting 38mpg in the city and 41mpg on the highway and that is trying really hard. When I first got the car I was getting 46-48mpg without trying and without have any hybird experience. I want to bring my car in before it hits 36k. Tire pressure and all the other stuff is okay. I did put new tires on but I don't think that would make that drastic of a differrence. I also find it is hard to track mileage the old way cause the tank is hard to fill. One thing I do notice is the batteries since to discharge fast and they are always low in the morning so the ICE works harder to keep the batt top off I am going to call them to see if they will look at it I have no warnins so we shall see.

Tony
 

·
Registered
Joined
·
928 Posts
As for new tires, you should check your speedometer/odometer. Set the cruise control for 60 MPH and see if you still average 60 seconds per mile marker. Also, see if the trip meter shows a difference in 10ths of miles driven after 10 or so miles compared to the mile markers.
 

·
Registered
Joined
·
17 Posts
The tires are the exact same size and I checked my speedo by gps and it is the same as with the stock tires. I am going to check my pressure again and up them alittle


Tony
 

·
Registered
Joined
·
1,661 Posts
TonyMS said:
The tires are the exact same size and I checked my speedo by gps and it is the same as with the stock tires. I am going to check my pressure again and up them alittle


Tony
Your mileage will drop with new tires until the treads wear a bit. Same thing again after first tire rotation. (Thanks The John!)
 

·
Registered
Joined
·
2 Posts
New tires

I just bought new Bridgestone Potenza G009 tires. My mileage dropped 10 per cent. I was getting 47-50, now I get 41-42. Bridgestone said I can expect my mileage to drop until the tires wear a little -- 8-10,000 miles.
 

·
Registered
Joined
·
3 Posts
gas mileage

i get the same gas mileage (43 mpg). yet i know that it's due to the fact that i live in a hilly area (glendale, ca) also the 2 fwy is on an incline as well. i'm sure that if i lived in kansas. i'd be getting better gas mileage.
 
1 - 20 of 26 Posts
Top