Changed tires and gas mileage is down

[diandtom]

My wife's car a 04 Buick Rendezvous with 45,000 miles is getting 3-4 mpg after changing tires. I got the same size as what came on the car. I did change brands. we were getting 24- 25 everyday driving and now it is 23-23. On a trip it would do 28 mpg and now 25 mpg. The car seems to be running perfect, just the mileage is down. Yesterday on a trip to Myrtle back and back it did 23.5 mpg. I know this is not a rv question but wondering if anybody had this problem ?
Tom

[diandtom]

My wife's car a 04 Buick Rendezvous with 45,000 miles is getting 3-4 mpg after changing tires. I got the same size as what came on the car. I did change brands. we were getting 24- 25 everyday driving and now it is 23-23. On a trip it would do 28 mpg and now 25 mpg. The car seems to be running perfect, just the mileage is down. Yesterday on a trip to Myrtle back and back it did 23.5 mpg. I know this is not a rv question but wondering if anybody had this problem ?
Tom

[doc]

Tom, if you have a GPS, make a comparison with what it says and the speedo says. Tire height is different on two I just bought for the Element. That would change the speed and odometer some.
But that much change in MPG is significant!

[Mutha]

Tom, I do not think your new tires are the cause of less fuel economy. My guess is you just got your first tank of "WINTER FORMULATION" gasoline.

It is well known that "WINTER" gas gets less mileage per gallon than "SUMMER" gas.

Anytime the government (EPA in this case) meddles with something that works good, you can bet it will be worse when they get through messin' with it! LOL!

Glenn

[Ray,IN]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Mutha:
Tom, I do not think your new tires are the cause of less fuel economy. My guess is you just got your first tank of "WINTER FORMULATION" gasoline.

It is well known that "WINTER" gas gets less mileage per gallon than "SUMMER" gas.

Anytime the government (EPA in this case) meddles with something that works good, you can bet it will be worse when they get through messin' with it! LOL!

Glenn </div></BLOCKQUOTE>

[diandtom]

I got the tires in August and after a tank or two the mileage started going down. I have bought gas without alcohol and that did not help. I did a reset on the DIC half way to Myrtle Beach, but I am sure it running winter gas in it. Doc, I will check it with the GPS next time out.
Tom

[Ray,IN]

You said "after a tank or two the mileage started going down"; this leads me to believe tires are not the cause or you would have seen any mileage difference at the very next tank. How long since the air filter has been changed? If you wait until the indicator says it's time to change, you will have noticed a mileage drop.

[diandtom]

Ray, I changed the air filter after I noticed the mileage going down. I usually change the air filter every 20K miles.

[GaryKD]

Hi Tom,
Assuming all other things being unchanged, consider checking the Treadwear Grade of the tires you had and now have. A lower Treadwear Grade could mean a softer tire and that may mean less fuel mileage.

[diandtom]

Gary, the car came with Firestone tires made in Mexico. The whole car was made in Mexico! Now I have TOYO tires made in China. Where I get my tires he recommed these over Michelins that I wanted. I am not happy with the tires as they are a little ruff until they warm up. I will not buy anymore TOYO tires. They are suppose to be a good quality tire.

[diandtom]

I just drove the car to New Bern and back and took the GPS with me. The car speedometer and the GPS are reading the same, so I guess I can rule out different tires sizes.
Tom

[GaryKD]

Since you have so few miles on the tires, consider returning them to where you made the purchase. Buy the Michelin tires you wanted. Living with tires you do not like means several years of irritation. The tire store may not give you a full credit toward the Michelins, but it should be pretty close.

[diandtom]

Gary, I have done business with this tire store for a long time. I now got over 6K miles on the tires. He did for 30 days offer me to exchange them and give me full credit. It was after 30 days I found the mileage dropping off. I should have got the same tires that came on the Buick. The Michelins that I wanted had a very agressive tread pattern that he did not hink I would like. I am going to take the car to a mechanic that fixed another Buick that the dealer could not fix. It going to have to wait until we get back from Florida.

[Tom N]

Tom;

My new Odyssey came with Michelin Energy LX4 tires. Were these the tires you replaced??

Michelin® Energy™ LX4®

Energy™ LX4®

Fuel Efficiency, Plus Comfort. MICHELIN® Energy™ LX4® tires feature great fuel efficiency and a comfortable ride.

Features and Benefits

Go Farther with Each Tank of Gas

EnergySaver Construction™ helps deliver excellent fuel efficiency by requiring less effort from your engine.

Feel Every Curve

A European handling profile, featuring a rounder shoulder, is designed to provide progressive, predictable cornering, letting you push your vehicle to the edges of its performance capabilities.

Quiet, Comfortable Ride

MICHELIN Comfort Control Technology™ uses computer-optimized design and precision manufacturing to offer greatly reduced vibrations and road noise.

-Tom