What is the weight of our stock 15" rims?

Not a clue, but I bet it's pretty insignificant. I'm guessing it would be like carrying a full bookbag in your Prius as opposed to an empty one. You likely won't notice a thing when it comes to MPG.

 

<div class='quotetop'>QUOTE(usbseawolf2000 @ Jun 28 2006, 02:07 PM) [snapback]277901[/snapback]</div>

The original 15" rim is 6.45kg (14.2lbs)

You maybe see 20% down, about 42 MPG with the 17" tires. <_<

Ken@Japan

 

Does anyone know how much the 16" wheels on the Prius sold in Europe and the touring model in Japan weight would switching to them affect mileage significantly?

 

<div class='quotetop'>QUOTE(larkinmj @ Jun 28 2006, 02:42 PM) [snapback]277921[/snapback]</div>

The original 16" rim is 6.90kg (15.2lbs).
The mileage will be 10% down by OEM Michelin Pilot Primacy 195/55R16.

Ken@Japan

 

The factory rims weigh around 15 pounds. I weighed one, so I know for sure rather than what is posted online somewhere. I also know that after I went from the stock wheels and tires, which weighed 32.2 pounds, to a 17" tire/wheel combo (Scion tC wheels) which weighed 42.8 pounds, I only went from 52 mpg to 51.7 mpg.

Don't listen to the naysayers, most of hem have not done it, and are only guessing. I have done it and know from experience.

Now I will say this. After switcing, you may end up driving faster because the car handles better. When I said that my mileage only dropped by 0.7 mpg, it was with me driving very conservatively. For me it was almost torture to go so low and steady, always at or just below the speed limits. I normally drive much faster and then my mileage dropped some more. If you look at my normal driving, I dropped from 48 to 43 mpg. But keep in mind that I drive around 80-85 mph for 60 miles. Not the ideal driving for max mileage. If you drive more reasonably, your mileage will NOT suffer that greatly.

Finally, it is possible to get a 17" setup that weighs less than the stock 15" wheels. I just ordered some wheels/tires which will weigh 1 pound less than the factory setup. I did thi smore for the handling benefits than any mileage benefits. The new wheels won't greatly increase the mileage, maybe I'll gain back that 0.7 mpg. But the car WILL handle much better, and the TRD suspension will perform better with less unsprung weight.

 

<div class='quotetop'>QUOTE(usbseawolf2000 @ Jun 27 2006, 10:07 PM) [snapback]277901[/snapback]</div>

I'll add Ken's more detailed info to our FAQ now too.

 

docvjay...what rims/tires combo did you get and what did you do about the tire pressure ninitoring stems from the stock tires?

 

It isn't just the rim weight... you also need to factor the weight and rolling resistance of the tire. There are a great many variables but another large one is having the total package close enough in size to not have to recalibrate the computer, plus the backs and fronts must be close in diameter to avoid setting off any ABS or traction control codes. I would wager it is possible to obtain 17" wheels and tires that may provide better fuel economy, although the looks may not appeal to you.

 

<div class='quotetop'>QUOTE(powrfuel @ Jun 28 2006, 08:42 AM) [snapback]277972[/snapback]</div>

I originally replaced the factory setup with wheels tires from a Scion tC. They are 17x7.5" rims, 5x100 spacing, 45mm offset, with Bridgestone Potenze RE92 215/45 17 tires. As I posted above, they weigh 11 pounds more than stock for each corner.

The new wheels I ordered are Centerline RPM forged wheels, 17x7", 5x100 bolt spacing, 42 mm offset. They weigh 13.5 pounds. I also ordered a set of General Exclaim UHP 215.45 17" tires. They weigh only 18 pounds, which is 4 pounds less than the average tire of that size. THe Brifgestones weigh 22 pounds each. This combo will weigh in at 31.5 pounds, less than the stock 32.2 pounds.

As I said, this is not likely going to change the mileage a great amount. What it will do is improve handling. Race cars have extremely light wheels because of the increase handling, not the fuel efficiency.

For the current Scion wheels, I just left the wheels without the sensors. All that happens is the orange indicator light is on when driving. It does not adversely affect the car in any way. Now that I'm getting my final set of wheels (the Scion rims were placeholders, test subjects) I'm installing a set of TPMS sensors to enable the system again. THe ones that came with the stock wheels are still in the stock wheels. I'm selling them to someone.

 

Does a tire with great grip equate to a higher rolling resistance?

 

<div class='quotetop'>QUOTE(McShemp @ Jun 28 2006, 04:42 PM) [snapback]278203[/snapback]</div>

Usually, but not always. A tire's grip is a combination of what it's made of and the tire's tread design (or lack thereof).

A softer compound will almost always have more rolling resistance than a harder one with all else being equal.

However, usually things are usually not equal. There are a few tires that are available with differnet compounds in the same design. THe Yokohama DOT race tires are one example. They have a standard and a soft compund with the same tire tread and size.

Design also makes a huge difference. Compare a slick, a summer tire, a rain tire (like the Goodyear Aquatread), and a snow tire. Each is very different.

A company can make a tire with a softer compound and design the tread so that rolling resistance does not actually increase. Or the other way around. That is why there are so many brands and designs!

Tires designed to be "economical" such as the ones on the Prius are usually of a harder compound to reduce rolling resistance, but design the tread so as not to loose too much grip. THe ideal high efficiency tire would be rock hard and very narrow, but this would have nearly no grip. The ideal high performance tire would be really wide and really soft to maximize grip.

It's a game of trade-offs.

I'm getting a tire with much more grip, and I'm likely trading off some mileage.

It all depends on what is more important to you.




I just got my new tires in, and they are indeed light. I weighed them at 18.0 pounds exactly.

 

hi all. dont mean to steal this post.
but is it true that we shouldnt get after market wheels for the 2006 prius?? something about the tyre monitor thingy...

thanks in advance

 

<div class='quotetop'>QUOTE(cupcake @ Jun 29 2006, 03:07 AM) [snapback]278480[/snapback]</div>

No, not true.

 

hi
well i switched from the european 16inch wheels to 17 inches OZ superturisimo GT ,, and Dunlop P9000 205x45x17" tires,, forgot to check the total weight of the old 16",, but the OZ rims are as far as i know,, 5,5 or 5,9kg ,,, the 16" are heavier,, Yes tires are a little wider than original (195mm) .. My experience is the same as DocVijay , i didnt se any significant drop in milage if i drive the in the same way as before.....


Andreas

 

<div class='quotetop'>QUOTE(andreaswin @ Jun 29 2006, 07:21 AM) [snapback]278562[/snapback]</div>

casted:
from wheelweights.net:

17x7 20.7lbs [9.38 kg]
17x7.5 21.6lbs
17x8 23.3lbs [10.56 kg]

16x7 19.6 lbs (or tirerack's 17.6lbs) [8.89 / 7.98 kg]

 

thanx!! nice website wheelweights.com







<div class='quotetop'>QUOTE(NuShrike @ Jun 29 2006, 09:50 PM) [snapback]278742[/snapback]</div>

 

<div class='quotetop'>QUOTE(DocVijay @ Jun 28 2006, 09:52 AM) [snapback]278012[/snapback]</div>

Questions: 1) Must Toyota (i.e. Prius) TPMS sensors be used with the Prius system, or have TPMS sensors been standardized across manufacturers/models?
2) Does anyone make a TPMS receiver system that can get more information out of the factory Prius sensors. My last car read each tire's pressure inside the cabin. I found that very informative for adjusting tire pressure for large seasonal temperature changes. I would also like to be able to monitor the pressure of the spare tire on the display. I would like to add such a display to my new Prius when it arrives.

Dave H.