Super VXer
i did a serarch, and couldnt find an answer. sorry if i missed it. i was geting around 19 mpg everyday driving, 21 on road trips. i just changed wheels and tyres and i knew it would afect my mpg, but not this much. (32" cooper descovery stt) i just calculated my new gas mileage. 10.59 mpg. 50% decrease! is this all due to the new tyres and the sligte lift that was required to fit acomodate them. or is there something else wrong? my driving habbats have not changed, and im a conservitve driver.
Super VXer
Have you compensated the mileage shown on the odo, to reflect the new tire diameter?...Originally Posted by FlyingV77
Input your stock size & new size here, calculate the difference in %, then take your odo reading x that % value, add that many miles to your orig odo reading, THEN divide by gallons used.
Super VXer
i did think about that but how do i figure that out? is there a formula?
Last edited by FlyingV77 : 07/31/2010 at 09:09 PM
Super VXer
Insult me, then ask for more help???wow dub that was quick! but i bet you hear that all the timei did think about that but how do i figure that out? is there a formula?
Good idea...
Re-read my original answer...it's all in there.
Super VXer
thanks dub for the help. i didnt meen to ofend, i was teasin you. didnt see the link you posted untill after i replyed. im useing a not to smart phone, it doesnt always load everything on a page. i think i did the math right. the tyre size dif was 9.28%. so compansated i got 11.63 mpg. still seems like somethig is wrong.
Super VXer
damn. i hope he doesnt hear it from his significant otherwow dub that was quick! but i bet you hear that all the time
Super VXer
A good thing for you funny little boys to remember...
Whenever you point a finger at me or anyone else, there are three more, pointing right back at you...
Super VXer
where is the thumb? Everyone always forgets about the thumb.A good thing for you funny little boys to remember...
Whenever you point a finger at me or anyone else, there are three more, pointing right back at you...
Super VXer
We're talkin' A THUMB here right?
I'm guessin' you'll be able to figure that out all by yourself...
Super VXer
unless you do it Army style, then you gesture with the whole hand.
Super VXer
That decrease isn't completely out of the ordinary for a few reasons
Heavier tires obviously require more power to turn
If you went wider a larger contact patch creates more friction, requires more power
A more aggressive tread pattern with squared off blocks are harder to roll. Look at " fuel saving tires" they all have rounded off tread blocks and grooves
New tires in general see a decrease in gas mileage. They are heavier than their worn counterparts. Plus the deeper tread flexes more than a shallow tread. This means energy that could be going to moving you forward is going to flex those tread blocks and then to move you
In addition to that, you are also now less aerodynamic because of the height increase
Check your tire pressure too if that's too low it will hurt your mileage. With oversized tires the best way to determine air pressure is to draw a chalk or grease line across your tires and drive a few feet then see if it's worn even across the tread. If it's worn on the sides your pressure is too low if it's worn in the center your pressure is too high.
After your lift did you have an alignment done? Camber issues from an alignment can have a small effect on mileage because it causes the tires to not contact the road squarely
Last edited by etlsport : 08/01/2010 at 08:29 AM
"Engineers believe if it ain't broke, it doesn't have enough features yet"
Super VXer
That is low...I run three different sizes and that is lower than all three.
Things that could be wrong.
-Calculation
-PSI
I would start by unhooking the battery for thirty.
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