How to improve my MPG - Please help!
#11
01-05-2009, 12:52 PM
Re: How to improve my MPG - Please help!
We have noticed our winter mileage has dropped considerably but also that our tire pressure after driving several miles is down 2 or 3 lbs. So we are now overinflating the tires by that amount. We will have to see how much difference that makes but it should work.
#12
01-05-2009, 06:33 PM
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Re: How to improve my MPG - Please help!
Yes, increasing your tires' circumference by raising the air pressure will definitely result in increased ODO mileage distance for each gallon of fuel..
#13
01-06-2009, 07:14 AM
Re: How to improve my MPG - Please help!
What should the tire pressure be for winter driving and what should it be for summer driving?
#14
01-06-2009, 12:53 PM
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Re: How to improve my MPG - Please help!
Anything else is just inexperienced experimentation with random results.
#15
01-13-2009, 10:56 PM
Re: How to improve my MPG - Please help!
No, a smaller circumference will make the car seem to go more miles.
A larger circumference will travel more distance per revolution and make the mileage seem perhaps less.
Of course the increased inflation pressure will improve mileage, so the mpg loss may be less apparent.
#16
01-14-2009, 05:00 AM
Re: How to improve my MPG - Please help!
No, a smaller circumference will make the car seem to go more miles.
A larger circumference will travel more distance per revolution and make the mileage seem perhaps less.
Of course the increased inflation pressure will improve mileage, so the mpg loss may be less apparent.
A larger circumference will travel more distance per revolution and make the mileage seem perhaps less.
Of course the increased inflation pressure will improve mileage, so the mpg loss may be less apparent.
Please make certain to limit your tire's cold psi to less than the MAX rating on the sidewall of your particular tires for safety.
JeffD
#17
01-14-2009, 09:25 AM
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Re: How to improve my MPG - Please help!
"...relatively insensitive to inflation pressure..."
By what "measure", "relative" to what...??
10% normally vs only ~5% on a modern belted...??
Certainly not valid for calibrating speed radar via use of the patrol car speedometer.
By what "measure", "relative" to what...??
10% normally vs only ~5% on a modern belted...??
Certainly not valid for calibrating speed radar via use of the patrol car speedometer.
#18
01-14-2009, 08:34 PM
Re: How to improve my MPG - Please help!
All true, but the revolutions/mile of a modern belted radial tire is relatively insensitive to the inflation pressure so with higher PSI you get better MPG and a little harsher ride, not a change in revs/mile.
Please make certain to limit your tire's cold psi to less than the MAX rating on the sidewall of your particular tires for safety.
JeffD
Please make certain to limit your tire's cold psi to less than the MAX rating on the sidewall of your particular tires for safety.
JeffD
I run 48 psi in the tires on the FEH, they have 46,000 miles on them and no centerwear. The sidewall says 44.
I ran 44 in the michelins on the Highlander Hybrid. It's sidewall said 35, I think. I only got 33,000 on them.
Burst pressure on a modern radial according to the retread community is about 300 psi. Advertised sidewall pressure is a matter of regulation from the tire industry and has little actual bearing on the capability of the tire.
If either vehicle's tire pressure slips below 40, the mileage suffers by about 2 mpg.
Mark
#19
01-14-2009, 08:38 PM
Re: How to improve my MPG - Please help!
No mention was made of percentage diameter change or police radar,or what have you.
What was mentioned earlier was that a smaller circumference will produce a situation where more rotations per mile occur, such that the speedo will read high and the mpg will read low, while a larger circumference will provide the opposite, lower tire rotations per mile, so lower percieved speed and number of miles.
Mark
#20
01-15-2009, 09:51 AM
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Re: How to improve my MPG - Please help!
No Willard, what he meant was that old bias ply tires
used to grow in the center a lot
So what is your definition of...."a lot"....??
when over inflated, but modern belted radials
don't
Again, by what "measure'...??
because of the belt.
No mention was made of percentage diameter change
My POINT, exactly..!!
or police radar,or what have you.
What was mentioned earlier was that a smaller circumference will produce a situation where more rotations per mile occur, such that the speedo will read high and the mpg will read low, while a larger circumference will provide the opposite, lower tire rotations per mile, so lower percieved speed and number of miles.
Mark
used to grow in the center a lot
So what is your definition of...."a lot"....??
when over inflated, but modern belted radials
don't
Again, by what "measure'...??
because of the belt.
No mention was made of percentage diameter change
My POINT, exactly..!!
or police radar,or what have you.
What was mentioned earlier was that a smaller circumference will produce a situation where more rotations per mile occur, such that the speedo will read high and the mpg will read low, while a larger circumference will provide the opposite, lower tire rotations per mile, so lower percieved speed and number of miles.
Mark
