Sudden drop in mileage

Fiberbabe · 01-12-2006, 10:55 AM

I've got an '02 Prius, with which I've consistently averaged about 45 mpg. All of a sudden, my mileage has dropped to around 30! Within the last 6 weeks or so, I had an alignment, two new tires on the front, and my air filter replaced... and I've been *religious* in my observance of regular maintenance. My car is stored outside, but it's only been in the 30s/40s.

I'm a little frustrated ~ I've come to rely on the mileage, and now all of a sudden it's reduced by a third, and I don't think I'm doing anything differently!

Anyone have any ideas?

Schmika · 01-12-2006, 11:25 AM

Check the obvious..tire pressure. I noticed my '05 drop 10mpg and found ONE tire at 22lbs. I had a slow leak that needed repaired. I am a "tire nut" and it was still difficult to notice it that low by sight (it was rear tire)

Imagine what a change of 5 lbs in all 4 tires would do?

chuxter_1 · 01-12-2006, 11:27 AM

That's what my MPG is currently at. The weather in NYC has been rather mild (40-60 degrees), even though it's January. I haven't had a great MPG avg. since the first month that I owned the vehicle (August). It was in the high 40's- low 50's, but now stays around 30MPG or less!!! I haven't had any work done to the car except for a fixed flat.

Another funny/bizarre thing was that while I was getting pretty good MPG readings during the first month of ownership, I eventually found out that the dealership actually had my tire pressure all messed up. Tire PSI was much, much lower than what is recommended in the manual, and it was set backwards.

**Tideland Prius** · 01-12-2006, 02:26 PM

new tyres. Let them wear out a bit.

01-12-2006, 10:55 AM	#1
Fiberbabe Join Date: Jan 2006 Location: Portland, Oregon Posts: 1 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	I've got an '02 Prius, with which I've consistently averaged about 45 mpg. All of a sudden, my mileage has dropped to around 30! Within the last 6 weeks or so, I had an alignment, two new tires on the front, and my air filter replaced... and I've been religious in my observance of regular maintenance. My car is stored outside, but it's only been in the 30s/40s. I'm a little frustrated ~ I've come to rely on the mileage, and now all of a sudden it's reduced by a third, and I don't think I'm doing anything differently! Anyone have any ideas? __________________ <span style=\'font-family:Impact\'>Showing a Gaia good time since 2002...</span>

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01-12-2006, 11:25 AM	#2
Schmika Senior Member Join Date: May 2005 Location: Xenia, OH Posts: 1,622 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Check the obvious..tire pressure. I noticed my '05 drop 10mpg and found ONE tire at 22lbs. I had a slow leak that needed repaired. I am a "tire nut" and it was still difficult to notice it that low by sight (it was rear tire) Imagine what a change of 5 lbs in all 4 tires would do?

01-12-2006, 11:27 AM	#3
chuxter_1 Join Date: Jun 2005 Posts: 7 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	That's what my MPG is currently at. The weather in NYC has been rather mild (40-60 degrees), even though it's January. I haven't had a great MPG avg. since the first month that I owned the vehicle (August). It was in the high 40's- low 50's, but now stays around 30MPG or less!!! I haven't had any work done to the car except for a fixed flat. Another funny/bizarre thing was that while I was getting pretty good MPG readings during the first month of ownership, I eventually found out that the dealership actually had my tire pressure all messed up. Tire PSI was much, much lower than what is recommended in the manual, and it was set backwards.

01-12-2006, 02:26 PM	#4
Tideland Prius Super Moderator Join Date: Oct 2004 Location: Canada Posts: 13,755 My Car: 2005 Prius Package: B Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 11	new tyres. Let them wear out a bit.