55K MPG Lower than last Summer, what to do?

mauricefrank · 07-26-2006, 06:27 AM

Hello,

My 2004 Prius has 55,000 miles. Although my MPG is better now in the summer, it is not as high this summer as it was last summer, and last winter I noticed the lifetime average dropped more than the first winter.

Last summer most of my tanks were in the 53-55 range. This summer I am not doing much better than 51-53.

Do I need any service like an engine cleaning, A/C flush, or anything else other than an oil change? I do change the oil every 5K and rotate the tires every 5K.

I have had Michelin Harmony tires since last November (39K), and they ride very well.

About two third of my miles are highway, and I get better MPG on the highway.

Thanks for your advice.

Maurice Frank

p626808 · 07-26-2006, 07:50 AM

<div class='quotetop'>QUOTE(mauricefrank @ Jul 26 2006, 06:27 AM) [snapback]292480[/snapback]</div>

Quote:

Hello,

My 2004 Prius has 55,000 miles. Although my MPG is better now in the summer, it is not as high this summer as it was last summer, and last winter I noticed the lifetime average dropped more than the first winter.

Last summer most of my tanks were in the 53-55 range. This summer I am not doing much better than 51-53.

Do I need any service like an engine cleaning, A/C flush, or anything else other than an oil change? I do change the oil every 5K and rotate the tires every 5K.

I have had Michelin Harmony tires since last November (39K), and they ride very well.

About two third of my miles are highway, and I get better MPG on the highway.

Thanks for your advice.

Maurice Frank
[/b]

I have the same problem.. now 67K on my car..
I attribute it to the new tires.. (Michelin Hydroedges)
I think it might be the cause of your drop as well.
The harmonies.. (I believe) have more resistance than the OEM tires.. and need more revelotions per mile.
This would explain the 1-3 MPG drop we are experiencing.

Scott

**TonyPSchaefer** · 07-26-2006, 09:08 AM

There are many who have replaced the stock tires with others and have noted a drop. I have the stock Integra so I can't speak from personal experience.

What's the tire pressure you maintain?

FireEngineer · 07-26-2006, 09:17 AM

If your local gas supply swithced to E10 blend recently that will account for the drop.

Wayne

kirbinster · 07-26-2006, 10:20 AM

I too have noticed a drop, but I switched to Michelin hydroedges and the E-10 gas sucks. The MPG has dropped on my BMW due to the gasoline also.

usbseawolf2000 · 07-26-2006, 10:38 AM

Is it time to change the engine air filter? I believe the interval is every 30k miles.

Dennis

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07-26-2006, 06:27 AM	#1
mauricefrank Join Date: Mar 2004 Location: Atlanta, GA Posts: 6 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	Hello, My 2004 Prius has 55,000 miles. Although my MPG is better now in the summer, it is not as high this summer as it was last summer, and last winter I noticed the lifetime average dropped more than the first winter. Last summer most of my tanks were in the 53-55 range. This summer I am not doing much better than 51-53. Do I need any service like an engine cleaning, A/C flush, or anything else other than an oil change? I do change the oil every 5K and rotate the tires every 5K. I have had Michelin Harmony tires since last November (39K), and they ride very well. About two third of my miles are highway, and I get better MPG on the highway. Thanks for your advice. Maurice Frank

07-26-2006, 09:08 AM	#3
TonyPSchaefer Your Friendly Moderator Join Date: May 2004 Location: Far-North Chicagoland Posts: 10,498 My Car: 2004 Prius Model: Package: #9 Thanks: 39 Thanked 165 Times in 106 Posts Friends: 23	There are many who have replaced the stock tires with others and have noted a drop. I have the stock Integra so I can't speak from personal experience. What's the tire pressure you maintain?

07-26-2006, 09:17 AM	#4
FireEngineer Senior Member Join Date: Oct 2004 Location: SW-Side of Chicago, IL Posts: 1,155 My Car: 2010 Prius Model: IV Package: Solar Roof Thanks: 1 Thanked 50 Times in 38 Posts Friends: 12	If your local gas supply swithced to E10 blend recently that will account for the drop. Wayne

07-26-2006, 10:20 AM	#5
kirbinster Senior Member Join Date: Jun 2005 Location: Morris County - New Jersey Posts: 575 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	I too have noticed a drop, but I switched to Michelin hydroedges and the E-10 gas sucks. The MPG has dropped on my BMW due to the gasoline also.

07-26-2006, 10:38 AM	#6
usbseawolf2000 HSD PhD Join Date: Sep 2004 Location: Queens, NY Posts: 3,254 My Car: 2006 Prius Model: Package: #3 Thanks: 106 Thanked 178 Times in 111 Posts Friends: 59	Is it time to change the engine air filter? I believe the interval is every 30k miles. Dennis