For anyone who thought 17" wheels got bad mpg's :)

I got Three Touring with 17". To my surprise, not only the drive is great on LA roads, smoother than my Gen 2 (although in my 2007 I did pump my tires a bit higher than recommended), but after 3 weeks I am averaging 56 MPG without even trying!

 

Please let us know what your MPG says, after you go thru a full tank. (Your Prius looks very nice.)

 

UK Sales Brochure says 17 inch wheels have official test mpgs which in litres per 100 km work out to be substantially less than the 15 inch as follows:

Combined 9%
Urban 11%
Extra Urban 6%

I know these tests do not reflect real world experiences but the differences do look significant.

Note that I am comparing litres per 100 km because this gives more valid and useful proportions between the different test results.

1. Do real world figures reflect this level of difference?
2. Does anyone know WHY the difference is so great? Can it be just increased rolling resistance?
3. Why are no other stats affected, such as 0 to 60 times?
4. What are the plusses of the larger wheels, apart from the look of the car?

Posted via the PriusChat mobile app.

 

1) Very hard to tell - you get a car which grips better - you might drive it more enthusiastically, thus giving a skewed effect. Like owning a Porsche and a Toyota 4WD - both with similar l/100 on paper - one will be driven more enthusiastically!!

2) That's part of it, but also the energy required to rotate the extra weight of the wheel/tyre. Without a dynamics laboratory, it would be very hard to know for sure. Wind resistance too - a wider bluff area hitting the windstream. It's hard to imagine how a rotating tyre would affect it, but it apparently does.

3) - are they the same?

4) I did read a journalist said the car with 17" felt a little more composed on the road than the 15" he'd also tested. But, in most cases (though not all), 17s will ride a little rougher?

 

don't kid yourself, those numbers would be much better with 15's.

 

You tell 'em, bisco!

...and we're still waiting for that full tank report. Short trips don't mean squat. We want to see the REAL figures.

Me and my 15's are still "stuck" at a constant 62 mpg. PWR mode, Normal, Eco... doesn't matter. But I'm very happy with that. (I shut up, and just drive it!)

 

According to the UK Sales brochure the only specs that differ between 15 and 17 inch wheels are the mpg. 0 to 60 is listed just once without reference to wheel size.

Oddly the mpg figures for 15 inch differ for each type of the 3 official tests, but for 17 inch they do not differ between the 3 types of test. Maybe this is just an unreliable spec listing, I don't know.

Not too bothered about the looks but does the car look ok with the 15 inch wheels?

Posted via the PriusChat mobile app.

 

I've never seen one on 17" - I'm happy with the 15s.

I tend to prefer the smaller wheels on cars I buy - firstly because they generally ride better, but also because they're cheaper to replace.

 

Thanks, do u mean wheels or tyres are cheaper to replace?
(Digression: My Gen 2 has 16 inch wheels and the tyres are an unusual 195 profile so the tyres cost me a third more. Which adds up when you replace 4!)

Posted via the PriusChat mobile app.

 

Tyres - I'd expect 20-40% dearer. But it's difficult to compare, as most manufacturers don't make the same tyre in both 195-65-15 and 215-45-17. The latter may be more performance oriented (hence part of the price difference).

They both seem to be relatively common sizes - I had a VOLVO once with a size that fitted nearly nothing else, worse was a PEUGEOT in the '80s which had the "new metric size" tyres which never took off - they were almost impossible to source after a while, many owners changed wheels to suit tyres they could actually get.

 

looks great OP - im going with 11"s myself

 

I parked next to a Tesla Model X over the weekend, and it really did make my 17" tires look like those of a clown car. Not sure if it had 20" or 22".

I can only imagine the range of that thing would get had their engineers read Prius Chat or checked out the impact we are seeing on Fuely.com

 

I can't see why a 17 inch wheel should get much less mpg than a 15 inch one. All the evidence I've seen on Prius Chat is anecdotal, from what I've seen.

 

Assuming anecdotal isn't all exaggerated, there should be something in it. Physics is a precise science, but one small miscalculation or omission could throw the results way off.

 

According to studies that I have seen. A 17" rim will get 1 or 2 MPG less than 15" rims. The only argument that is true. 17" tires cost significantly more than the 15" tires.

 

My 2016 touring w 17" tires was in the shop for 8 days. I had a loaner, same model with 15". Driving my usual routes, with 2 long flat commutes, I can say that there is a big difference. I noticed as much as 10 mpg hit. After 380 miles the difference averaged out to 6 mpg.

 

And don't forget about the cost of tire replacement. Drivers like big tires and rims; they look cool. My buddy drives a Beamer. 17 mpg. But he loves that car, top down, hair blowing in the wind..... his tires cost $400. Each! They wear out and need to be replaced every 20k. Do the math.

 

Let's see what size/type of tires show up on the Tesla model 3

 

I think it was car and driver that did a study and found small differences in gas mileage betwen 15" and 17" rims but not the 16" rims. Once you get to 18" and beyond that is when gas mileage takes a bigger hit. Again not scientific but they have some interesting observations. This was an issue in the last years Car And Driver