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Last week it was time to replace my tires. I went with GoodYear ASSURANCE WEATHERREADY. My MPG dropped from 40 to 35. Anyone had similar experience. Is this a norm?
 

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I had same happen on both of my hybrids and on associate Prius.

Pull ECM fuse out for few minutes to reset it. His dropped from over 40 to 25 - fuse fixed it.
For what it is, you should have better mpg, as now you have a larger diameter tire and it covers more ground in single rpm.
 

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I had same happen on both of my hybrids and on associate Prius.

Pull ECM fuse out for few minutes to reset it. His dropped from over 40 to 25 - fuse fixed it.
For what it is, you should have better mpg, as now you have a larger diameter tire and it covers more ground in single rpm.
ECM fuse? Is it safe to reset in hybrid? I read I should supply 12 volts with battery tender when replacing 12 volt battery in order not to reset system.
 

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Fuse. NOT BATTERY.

From this diagram here - yours may be somewhat different - it's fuse 24 . Whatever says ECU on the fuse box lid. Also, remember that lid is mirror image, it gets a bit screwy sometimes to refer to proper fuse.
Fuses are perfectly safe to remove. You will likely lose your mpg data, possibly, time and radio presets, though maybe not. Small price to pay.



https://www.autogenius.info/toyota-avalon-hybrid-from-2013-fuse-box-diagram/


I had fuses pulled many times on my hybrids and on any car ever owned.
 

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Fuse. NOT BATTERY.

From this diagram here - yours may be somewhat different - it's fuse 24 . Whatever says ECU on the fuse box lid. Also, remember that lid is mirror image, it gets a bit screwy sometimes to refer to proper fuse.
Fuses are perfectly safe to remove. You will likely lose your mpg data, possibly, time and radio presets, though maybe not. Small price to pay.



https://www.autogenius.info/toyota-avalon-hybrid-from-2013-fuse-box-diagram/


I had fuses pulled many times on my hybrids and on any car ever owned.
Thank you for the info. Much appreciated.
I will try.
 

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I don't understand how this works. How does resetting the ECU change the MPG?
 

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I had the same thing happen to me. Weatherbeater tires seem to be good, but in the six months that I've owned them I had gotten four flat tires, two required being replaced becuase of the object being in the side radius. I've gone back to Michelin on the replacements.
 

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When I replaced the original tires on my 94 Civic VX with Michelins, the MPG dropped by 10 on average, that's fill amount divided by miles travelled for every mile and every gallon of fuel, over 10 thousand of miles. The MPG actually goes down when you compare a new tire to one with 75% of the tread gone (on it's last leg). I had averaged very close to 60MPG on the original tires on the VX but they were 15 years old and I was worried about a blowout trashing my new paint job.

Every wheel tire assembly is basically a flywheel, as the tire mass reduces with wear, the flywheel gets lighter and weight at the furthest distance from the axis of rotation is much more significant than weight at the center, as far as the energy it takes to just spin the tires.

I can tell on my Echo the coasting distances have increased as the tires have worn to about half of their original tread depth. Every tire's rolling resistance gets lower (better) as the tires wear down since there is less material to flex in the tread and the "flywheel" effect is reduced by lower weight in the tread rubber due to the wear.

It's best to do research on rolling resistance before buying replacement tires. It's a balance between longevity, traction, and economy. Hybrid manufactures have used low rolling resistance tires to get their EPA ratings up to the maximum, but typical low rolling resistance tires are not great for wear or handling since it is a trade off between those characteristics.

I coasted today on my way home the last 1.1 miles with my engine shut down in neutral. That single act added .2 MPG to my current tank at over 450 miles on a 11.9 gallon tank with a little less than 1/4 tank left. I dread replacing the tires on my car now, Bridgestone Ecopia EP422's when they will no longer pass inspection. They have feathering wear issues that make them noisy and I'm trying to figure out what's next for tires on 5.5 X15" rims that weigh 12 pounds each. I think I have decided on Vredestein 175x55x15s, versus the 185x60x15s. That will increase the revolutions per mile and lower my correction factor for mileage from 6% to about 3%.
 

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Every time I do anything that would affect the odometer reading, I check the revolutions per mile compared to the tire I am replacing and then I drive the car on a known combination of roads that are 19.9 miles from my house. The odometer reading's difference compared to the 19.9 mile distance gives me a correction factor for calculating MPG.

The previous post about wear changing the overall diameter of the tire is correct, but how significant? Lets say the tires are worn down 8/32nds which takes an 11/32nds new tire down to 3/32nds, which won't pass inspection here (worn out).

That's a radius change which doubles considering diameter is two radii, so 16/32nds or half an inch. On a 30 inch diameter tire, it wears to 29.5 inches. Since PII is the same at 3.1416, the change is .5/30 or 1/60th of the diameter or 1.66% correction factor, meaning you would have to use .9833 to multiply your distance travelled to get the corrected actual distance. 1000 miles would actually be 983.3 miles.

Edit:
Another way to check your odometer accuracy is to drive on a road that has mile markers (like Interstates) for over 100 miles, resetting the trip odometer at the beginning of the trip and checking the reading at the 100 mile mark. This is the accuracy of your odometer, including every factor that could affect accuracy.
 
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