I just got a set of snow tires installed on the 07 Prius. Cheap black steel wheels, with 195/65-15 Bridgestone Blizzak REVOs. Inflated to the same 42 psi F/40 psi R that the stock tires were using. I am curious what this might do to my MPG. Both the real MPG and - since the tires are 195 not the 185 of the stock tires - the reported MPG? Any similar experiences?
<div class='quotetop'>QUOTE(John L. @ Dec 22 2006, 03:38 PM) [snapback]365848[/snapback]</div> I guess I should be more clear. I realize that the stock and snow tires have different diameters. Stock Goodyear Integrity 185/65-15 diam 24.4" rev/mile 855 Snow Bridgestone REVO 195/65-15 diam 25.0" rev/mile 833 So from a purely "geometric" point of view, the larger tires could cause my "reported" speed and MPG to be overstated by 855/833 = 2.6%. But is it more complicated than that? Do the larger tires make the car less, or more, efficient?
I think that since you are driving on snow, you shouldn't worry about the gas you might save. Your life is probably a bit more important. Don't get carried away with MPG.
I have installed the 185/65X15 tires (Michelin Ice) on my 07 Touring Prius and have now put 2500 plus miles on them. I have only noticed about 1 mpg difference. However it is getting colder up here in the Northeast and I feel that is mostly what is causing the loss in mpg. I still seem to average 46-47 mpg with mostly highway driving at 70-75 mph.
I installed my steel wheel with michelin x-ice tires a week ago and have seen a small increase in mpg so far.No winter so far here in ct so will see if snow and ice brings gown the mpg.
Compared to the "all season" Michelin Harmony tires I run, I took a pretty big hit when I put on the new Goodyear Nordic studded snow tires back in November. No difference in city fuel economy that I could determine, but on the Trans Canada a given stretch at the same 105 km/h, I could expect 5.2 l/100km from the Harmony. With the studded Nordic, try 6.5 l/100km. So the Harmony was 54 mpg and the studded Nordic is only 44 MPG. Though with the much better snow and especially ice traction, I could care less how much lower my winter highway fuel economy is. As another poster commented, Beats ending up in a ditch somewhere. FYI, the Goodyear Nordic is only available at Canadian Tire. In the EU it's known as the Goodyear Ultra Grip 500: http://eu.goodyear.com/home_en/tires/repos...p?page=benefits I'm out of here, off to the hobby farm. See you in January!
