HELP.. I lost 10 mpg with new Intergrity's

I believe others have posted that the OEM Integrities are slightly different than the replacement Integrities. The OEM's are made overseas and are low rolling resistance, I believe the replacements are slightly less so. Someone will probably chime in to provide the relevant facts.

I always have alignment done when new tires are installed. I've got enough invested in a set of new tires that it is not worth risking wrecking a pair of tires in short order because they are not properly aligned.

You can expect a break in period as well and it could take several thousand miles to get back to normal.

I assume you are aware of the correlation of cold weather and poor mileage. Has your weather over the past week been cooler than normal?

 

I would tend to discount only 1 week of data / 1 tank of data, especially given the inconsistent pump shutoff point due to the Prius bladder. Give it more time to gather 3 or 4 tanks of data, then use the cumulative data over several fill-ups. Plus, 1 week of mpg data could be severely thrown off by your weather conditions and use of cabin heating in the winter. Didn't you notice the seasonal change in MPG over the past couple years with your Prius? I notice it, even here in mild San Diego. My MPG (by MFD or ScanGauge) will vary by 5 MPG over the course of a year due to outside temperature effects. Other climates should see a dramatically larger swing.

 

i would also suggest you to check the tires for free rotation. sometimes, your brakes can cause drag, maybe a wearing wheel bearing, something that is creating friction in the wheel assembly.

check it out, it's just a matter of spinning the tires, then you got peace of mind.

good luck, post what you found out here.

 

I just replaced two OEM front tires with Yokohama AS430s and have taken a 6-7 MPG hit. I did have an alignment done at the Toyota dealer that sold the tires. Is it possible that the tire selection could make that much difference? I have put 1500 miles on the new tires an there is no improvement. Thanks for any help.

 

Tires can indeed make a significant change is mileage. I recently changed tires & lost MPG. It has improved since original installation & I did have it aligned when the tires were installed. I made several changes & cannot determine the exact cause of the loss of mileage but suspect the tires were the primary cause as explaned next.

I added the splash guards & they could very well make a negligible change.

I changed from 185/65/15 tires to 195/60/15 as I felt the car was slightly "under tired". I typically run Michelin tires but have a Kumho dealer a few miles from me & decided to give the Kumho Solus KR 21's a try.

Results? I immediately dropped a minimum of 5 mpg. The first tank ran 39.8 mpg but also at 70mph, hills & wind. After a few hundred miles I was back into the low 40's. I now have approximately 1,300 miles on the tires & just finished 445 miles, combo highway/town & over 90% highway and I got 50.6 MPG. I definitely think you need to have your car aligned & put some miles on the tires. The initial 10 mpg loss seems recouped at this time & hopefully I will gain a couple more miles per gallon.

I still don't know what to think of the tires but they are certainly smoother & quieter than the originals. The most noticeable difference is handling. Impressive! The vehicle is significantly more responsive & more stable no matter the wind speed or direction. It is certainly worth a 1-2 mpg difference. If I ever have to make any safety maneuvers, the slight loss of fuel mileage (if it actually is) will certainly be worth it.

Give it some time & I think you'll see an improvement.

 

Do bring your alignment numbers here for review and comment.

Bob Wilson

 

Going from memory, they still are the lowest rolling resistance tire for the Prius, but not as low as the OEM. Wish I could remember what thread this was discussed in. (If I'm spouting BS about the Integrity, somebody please correct me.)

Did you figure mileage from the fill or from the MFD? The MFD is far more accurate for individual tanks, but the calculated mileage will be accurate over the long haul. The fill variability with the bladder tank is extreme, especially in winter as I am learning.