Impact of Model Five Low Profile Tires on MPG?

I think the tires may have a minor affect on your overall MPG numbers, but I also think that there are many other variables that may lower your MPG. Things like terrain, temperature, driving style, trip length and others will have a larger net impact on your MPG in my opinion than your tires.

I have nearly 17,000 miles on my 2011 V/Five and in 10 months and have yet to get a calculated MPG lower than 50 MPG my average is 52.6 MPG lifetime approximately 32 fill-ups. I also have the non LRR Brigestone Turanza EL400-02's tires and I use E10 fuel.

 

http://priuschat.com/forums/other-c...eage-no-its-your-gallonage-really-counts.html

 

It's relevant because whatever the drop is, it's not that big a difference when you compare gallonage. Do some calculations yourself on gallonage over 100 miles using hypothetical figures like these: 50 mpg vs. 45 mpg, 20 mpg vs. 19 mpg, etc.

This might help too: http://priuschat.com/forums/gen-iii.../65496-17-wheels-effect-mpg-2.html#post909868. I see a delta of 1.8 miles per UK gallon in their combined test. That's ~1.5 miles per US gallon, in their test. And 70.6 (miles per Imperial gallon) = 58.7867731 miles per US gallon.

 

My understanding, from discussions at intro, was that the EPA label is a weighted average of all models. The V (now Five) was configured close enough to the others that it didn't require a separate rating. But as intro event attendees learned, its raw mpg figures were noticeably lower. Paradox's experience of 3 mpg loss seems in the right range.

 

Paradox is definitely in the ballpark. The GenII suffers a greater drop with 17s to the tune of 4-6mpg. This has been verified by many other owners.

We often hear owners of the Five model who claim no loss but IMO their claim is invalid because none of them have never swapped their 17s for 15s to see if their mpg increases. Claiming no loss just because you can meet EPA ratings doesn't mean squat because many people find it easy to beat the EPA rating while others don't even come close. There are just too many variables that determine average mpg.

 

I can't speak for big differences in mileage, because 17's are all I've ever had. Since I drive a mile to work and back, I'm used to poor mileage (and worse since I go through Chicago winters) - and it would be the same poor mileage with 15's. But... when I'm on long trips, I easily get mid-50's with the 17's. I have never wanted smaller wheels to gain a better mpg. 17's just do it in style!

 

Correction. It would be the same winter mpg drop but the 15s would still produce higher mpg.

I agree though. The 17s are just soooo much nicer than the 15s. They are safer to boot!

 

JW,

I respect your opinion as our resident wheel and LRR tire SME, but I feel beating or meeting the EPA est. does matter. The V's wheels/tires have an impact on the overall MPG the potential 3 MPG difference vs. the 15" wheels could be overcome buy minimal hypermiling techniques. Granted the person with 15" inch wheels would have a higher MPG number naturally they could also do better if they tried. Like I said earlier there are too many variables that will affect overall net MPG I am happy to beat the EPA est. and just wanted to let the OP know that the 17's affect is negligible in my experience. If I were to come across a set of stock 15 inch wheels I would experiment and run them for a couple of months and see how much of an MPG increase I would get. One of the main reasons I bought the V was the larger 17 inch wheels, I am not to big on appearance mods. If the car was not my daily driver and I had more time and money I would do some functional suspension upgrades and mods.

Hope you’re doing okay and hanging in there?

 

NP my friend.

I think we are looking at this from two different angles. I am basically saying that the 17s WILL cause a drop in mpg compared to the 15s by approx. 2-3mpg. In the grand scheme of things this is indeed negligible unless someone is big into hypermiling. In which case the 15s will offer greater ability to squeeze out more MPG than the 17s and thus widen the gap for potential max mpg.

So my point was simply that being able to reach EPA ratings with the 17s doesn't mean that you couldn't do even better with the 15s.

I'm doing fairly well. Still on chemo but hopefully I'll have a scan soon and see if there are any more tumors.

 

That's an important thing for people to understand if their primary concern is saving fuel costs.

But...MPG counts just as much as a ball game score if that's what important to the driver and they are keeping score.

Life is more than counting money.:rockon:

 

We have the Michelin Pilots in 215/45R17 on alloy rims as our stock wheel. We also have Michelin X-Ice2 in 195/65R15 on steel (Corolla) rims, for winter.

With the couple of swaps I've done so far, the subseqent tank's mileage has been very similar. That's going from stock 17" all-season to 15" snow tires. What I glean from that is that 17" vs 15" mileage hit is roughly equivalent to snow vs all season hit.

 

Congrats!!! :rockon:

 

Good point: the 195/65R15 do almost 2% fewer revolutions per any given distance, comparing to 215/45R17. This will (maybe) lower gearing a bit, and cause the car to underestimate distance travelled.

I'm curious what 15" OEM's (say something like Ecopia EP20 195/65R15) on steel rims would yield for mileage.

I really didn't notice any difference in feel, going from 17" OEM to 15" Michelin X-Ice. D.O. for my wife, who uses the car mostly: about a week after the latest swap to snows I asked how they were feeling, and she said she'd forgotten they even were switched.

 

Aye, average revs/mile for the 195/65/15 = 833. The average revs/mile for the 215/45/17 = 844.

If you really didn't notice a difference in feel from the 17s to the 15s then I suggest testing them in terms of handling. The 17s seriously stick to corners with little sidewall flex. With the 15s it feels like they are going to peel off the wheel. lol I'm teasing, don't go hammering the corners.