mileage problem

[FlyingV77]

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.

[Ldub]

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?

Have you compensated the mileage shown on the odo, to reflect the new tire diameter?...:naughty:

Input your stock size & new size here (http://www.1010tires.com/tiresizecalculator.asp), 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.

[FlyingV77]

i did think about that but how do i figure that out? is there a formula?

[Ldub]

wow dub that was quick! but i bet you hear that all the time ;) i did think about that but how do i figure that out? is there a formula?

Insult me, then ask for more help???

Good idea...:yesgray:

Re-read my original answer...it's all in there.

[FlyingV77]

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.

[ZubrAZ]

wow dub that was quick! but i bet you hear that all the time ;)

damn. i hope he doesnt hear it from his significant other

[Ldub]

damn. i hope he doesnt hear it from his significant other

A good thing for you funny little boys to remember...:slap:

Whenever you point a finger at me or anyone else, there are three more, pointing right back at you...:yesgray:

[circmand]

A good thing for you funny little boys to remember...:slap:

Whenever you point a finger at me or anyone else, there are three more, pointing right back at you...:yesgray:

where is the thumb? Everyone always forgets about the thumb.

[Ldub]

where is the thumb? Everyone always forgets about the thumb.

We're talkin' A THUMB here right?

I'm guessin' you'll be able to figure that out all by yourself...:yesgray:

[FlyingV77]

unless you do it Army style, then you gesture with the whole hand.

[etlsport]

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

[JHarris1385]

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.