17" rims and fuel economy

[songa]

hey guys...anyone here running their yaris on 17" rims? although i love my FE on my stock (15" steelies), i am starting to consider putting 17" rims on there because of the looks. however, how drastic will this change affect the FE? lets assume that the 17" rims are about 20-21lbs each, which should be about 3 or 4lbs heavier than the stock 15" steels (which are around 17lbs each if im not mistaken). with that total of 12-16lbs heavier wheels, how much will that hurt the FE? and does it also depend on the diameter of the tires as well? i plan on using 205/40/17 tires. im not sure how much they should weigh tho. maybe this quetsion is a little too hard to answer =P if anyone has their own experience with 17" id like to hear them tho at least ! thanks

[puetato89]

i love my 17"s.... and the mpg didnt change much... but the turning radius is a bit decreased... i dont know if me being lowered has anything to do with the mpg

[songa]

ahh i love the yaris turning radius! how much do your 17"s weigh?

[thebarber]

well, i have 14" steelies which weigh around 14lbs (i think 15" steelies are 15 or 16lbs) with 185-60-14 fuzion hri's

crandall has 17x7 tenzoR rims w/ 215-40-17 general exclaim uhp tires - - i think the rims weigh 18 or 19lbs....so not THAT heavy by 17" standards

we're both 5 speed, both live in the same town and he gets about 50km (+/- 30miles) less per tank than i do. he's dropped on tein basic coilovers and i KNOW he takes it easy accelerating....and he doesnt really speed. i drive moderately aggressively and i take off quick from lights. i also have an intake.

ive driven crandalls car too....i notice HUGE acceleration and braking difference between our two car (intake or not).

heavy 17's, in my opinion, arent a good idea for small, light cars with small engines and low hp - - if youre concerned about acceleration, braking or economy, that is...

[jambo101]

I'd keep the original 15 inch with snow tires and get summer tires on the 17's for spring,or do you plan on getting snows for the 17's=very expensive.

[songa]

what about all seasons on 17's?

[thebarber]

Originally Posted by songa

what about all seasons on 17's?

not to run year round...

[MadMax]

But remember, if you add 17" wheels then you need to multiple the distance driven by 1.07 to get the exact mileage, due to the larger wheel diameter...

So when I drive an "indicated" 350 miles, in reality it is 374.5 miles...

Cheers! M2

[thebarber]

Originally Posted by MadMax

But remember, if you add 17" wheels then you need to multiple the distance driven by 1.07 to get the exact mileage, due to the larger wheel diameter...

So when I drive an "indicated" 350 miles, in reality it is 374.5 miles...

Cheers! M2

not really...its all about tire size

oem is 185-60-15

205-40-17 are within 1.23% of the oem rolling size

215-40-17 are within 0.125%

really, youre only going about 1% farther rather than 7%...

[puetato89]

Originally Posted by songa

ahh i love the yaris turning radius! how much do your 17"s weigh?

all 4 was 44lbs... with tires it was i believe about 52-56lbs range... on 205/40/17

[jambo101]

Originally Posted by songa

what about all seasons on 17's?

All seasons might be ok for southern climates but if you are in the snowbelt i'd recommend the dedicated snow tire.

[MadMax]

Originally Posted by thebarber

not really...its all about tire size

oem is 185-60-15

205-40-17 are within 1.23% of the oem rolling size

215-40-17 are within 0.125%

really, youre only going about 1% farther rather than 7%...

My Yaris has 215/45ZR17 tires on it, and stock tires are 175/65R14s.

Go to this web site and submit those two sizes in, and you will see that the stock tire has a circumference of 72.09 inches (1831mm) whereas the larger tire I am running has a circumference of 77.31 inches (1963.6mm). That's a diameter difference of 6.75%.

Do the math and you will see the tire travels a distance of an additional 5.22 inches per rotation over the stock tire.

As the odometer is set for the stock tire, you must add the addition of 7% (rounded up) to the odometer distance traveled.

[thebarber]

Originally Posted by MadMax

My Yaris has 215/45ZR17 tires on it, and stock tires are 175/65R14s.

Go to this web site and submit those two sizes in, and you will see that the stock tire has a circumference of 72.09 inches (1831mm) whereas the larger tire I am running has a circumference of 77.31 inches (1963.6mm). That's a diameter difference of 6.75%.

Do the math and you will see the tire travels a distance of an additional 5.22 inches per rotation over the stock tire.

As the odometer is set for the stock tire, you must add the addition of 7% (rounded up) to the odometer distance traveled.

it is suggested you dont go past 3% tire size difference....just because it screws up your speedometer and odometer too much otherwise...

[MadMax]

Originally Posted by thebarber

it is suggested you dont go past 3% tire size difference....just because it screws up your speedometer and odometer too much otherwise...

I have never heard that one before, can you cite your source? Plus, if anything, that is probably a rule for stock rims, on which you can put slightly larger tires. But mine are aftermarket.

Plus, I own a Jeep, so I am very familiar with oversized wheels and tires! It is very common in the Keep community for people to put huge tires on their rigs. Besides suspension modifications, the only real requirement for larger sizes is regearing (for going from 29" tires to 35" or larger); but that is not an issue here.

The stock Yaris with an AT can easily handle 17" wheels, and you can even lower it by changing out the springs to some degree without having rubbing issues. People all over this forum have done this, and there are numerous threads about it

Cheers! M2

[thebarber]

Originally Posted by MadMax

I have never heard that one before, can you cite your source? Plus, if anything, that is probably a rule for stock rims, on which you can put slightly larger tires. But mine are aftermarket.

Plus, I own a Jeep, so I am very familiar with oversized wheels and tires! It is very common in the Keep community for people to put huge tires on their rigs. Besides suspension modifications, the only real requirement for larger sizes is regearing (for going from 29" tires to 35" or larger); but that is not an issue here.

The stock Yaris with an AT can easily handle 17" wheels, and you can even lower it by changing out the springs to some degree without having rubbing issues. People all over this forum have done this, and there are numerous threads about it

Cheers! M2

jeep is a different story though...i have a buddy on 35's....he changed the gearing in his speedo though

as for a source of that 3% rule...1010tires.com, the place you linked to goes red if you put in a size thats 3% larger than your stock tires on the tire size calculator...see:



the tires you bought are sized for a corolla.....

[MadMax]

I didn't get that message, and numerous people on here have put on 17" wheels without problems. Plus, I may be relatively new to the Yaris; but this isn't my first rodeo! The Yaris is light enough and the brakes adequate to handle the larger wheel. You may lose a little lower-end acceleration but you gain it back on the upper end.

As for Jeeps, I hope he regeared more than his speedo if he offroads, as his differentials are going to explode one of these days if he puts the stress of 35s on them with the stock gearing! He needs to regear to 4.88 with 35s to get the low-end back. Without that, he'll be very slow off the line and be downshifting at every hill even if he doesn't offroad.

[TLyttle]

Welll.... One of the big flaws to current tires as I see it is the width. If wide tires were efficient, then bicycles would have wide tires, right? Every try pedalling a bike with fat, small-diameter wheels? It ain't easy... Same thing applies to any wheel: the larger the diameter, the less rolling resistance. The narrower the wheel, the less rolling resistance. All this rolling resistance has to do with fuel economy.

As far as snow is concerned, the same thing applies: my neighbour goes over a gravel pass in the winter, and none of the 4x4s, no matter what tires they have, can follow him. What's he driving? A Model T. 30" diameter, 3 1/2" wide tires. He can drive through a foot of snow with no chains or other traction devices. Gee, why is that?

I had a set of late-technology snowtires on my Volvo; they worked, but now I have a set of narrow-section (75%) tires on there, and they are much better in the snow (they don't plow as much), and my FE went up.

Something to consider...

[thebarber]

Originally Posted by MadMax

I didn't get that message, and numerous people on here have put on 17" wheels without problems. Plus, I may be relatively new to the Yaris; but this isn't my first rodeo! The Yaris is light enough and the brakes adequate to handle the larger wheel. You may lose a little lower-end acceleration but you gain it back on the upper end.

As for Jeeps, I hope he regeared more than his speedo if he offroads, as his differentials are going to explode one of these days if he puts the stress of 35s on them with the stock gearing! He needs to regear to 4.88 with 35s to get the low-end back. Without that, he'll be very slow off the line and be downshifting at every hill even if he doesn't offroad.

no problems? but you said yourself that odometer is off 7%, that means your speedo is off too. as for acceleration, ive drive a yaris with 17's, and compared to my car w/ 14's, its a dog from a dig

as for my buddies jeep, its fairly extensively modded...he knows what he's doing....lol, i think! his screen name is highonlifeandglue on jeepkings.ca