Is there a thread that covers this specifically? Does the increased diameter/lower highway revs outweigh the increase in rolling resistance/tire weight? Have all those who've switched to the slightly bigger tire seen the same result? I'm looking into getting new tires but do not want to sacrifice any mileage...suggestions

The difference is only about 2% for the larger tire. My opinion is that it won't make much of a difference.

We just bought my wife a CR-V which has a built in mileage display and an instantaneous bar graph for mileage. Boy, does that thing make you want to accelerate slowly and ease of the gas once up to speed.

You will not see any difference at all.

I saw about a 1mpg less observed difference when I switched. I got about 22-24mpg regularly on the highway w/ stock tires, but about 20-23 with my new 225/70s.

This may or not be "actual" difference.

With my stock tires, my spedo/odometer were off by about 2mph at 60mph according to my GPS (and highway mile markers) My spedo read 62mph when I was doing 60. My odometer was off a similar abount. At 30mph there was very little difference between the car and gps measurements.

After I switched to 225/70 Cooper ATRs my spedometer was reading about 60mph when my gps was reading 60mph. When my spedo said 65mph my gps said 64mph. The odometer is just barely off as well.

My spedo and odometer are more accurate with the 225 tire. I might not have been getting slightly better gas mileage if I wasn't travling quite as far as I thought I was before.

I just got new tires today. (General Grabber HT-S 225/70-16) I'll take some carefull measurements of the odometer, spedometer, and mileage with these new tires to see how they compare.


In a nutshell....I think and difference would be minor, and in my case it was only for the better. I like the 225/70 size very much.

Will

This is good to know, great question :)

I'll be doing a write up on my new General Graber HT-S tire soon, but in the mean while:


I checked w/ my GPS trip meter and set the trip odometer on my E this morning.

It was 57.8 miles driven on the GPS. It was 57.3 miles on the car.
This means that I should be adding about 2 miles to the distance traveled when I fill up my car at about 200 miles traveled.

Using my last fill up for reference: 208miles (odometer) and 8.8 gallons = 23.6mpg. Using GPS miles that would be 23.8mpg.

These new tires read slightly short of true mileage. The stock tires were a bit over true mileage, but I didn't keep carefull records to help support this. Sorry. I think it is safe to assume that a measured 23.5mpg w/ the stock tires was closer to 23mpg.

With my new Grabbers:
At 60mph (GPS) the car reads 60.
At GPS 65 the E is saying 65.
At GPS 70 the E is needle is on the bottom of the 70mph mark. Hard to say...69-1/2? Close enogh for me.

At 35mph they were both about the same, but I didn't get any nice steady consistant streaches at that speed to know for sure.

I think 225/70 is a great size for the E.

Will