Newbie here, bought rims/tires, OMG, what a mistake

I'm curious because Toyota also offers (model 4) a 16" wheel with their sport package and the published MPG figures are identical to the 15" tire version.

 

Two reasons.

1. Because the 16" wheel with ultra-low rolling resistance tires does not cause a huge hit to fuel economy.

2. Toyota chose not to disclose the mpg loss. There is one, it's just not advertised.

If you use a non-LRR or one inferior to the OE tire the hit will become more evident. Jumping from a 15" to a 17" exacerbates this. Issue.

 

I read another forum somewhere else where they recommend to stick with the 15" stock tires and switch the rims to Konig Helium. I think the rims are like 9 pounds each. giving you an extra 4mpg.

 

I find it hard to believe there is a 4mpg gain from just a little weight reduction. It doesn't sound realistic.

 

Another forum somewhere

 

Agreed. The hubcaps have good aero, and most aftermarket wheels have crap aero, more than negating any weight advantage.

 

We could toss in the aero benefit of a narrower wheel and a high offset which keeps the wheels tucked. So many things to consider.

 

Hi F8L - need some advice. I put some snows on today - had them installed on the rims that came with the car. Discount Tire will charge $$ in the spring to swap the snows for my summer tires. Was thinking this might be a good enough reason to leave the snows on the rims and buy some spiffy aftermarket rims for the summer tires, but am reading that this will likely lower mileage. What do you think??????

 

I think you could get close to stock mpg or maybe a tad better with the right combo. If you got a nice set of lightweight 15" wheels and ran the Ecopia EP422 175/65/15 tire you shouldn't take a big hit like those who go to 16s or 17s.

If you have no fear of expensive wheels then the Enkei RPF1 is sweet at only 9.5lbs! They run about $812 for a set.

The Kosei K4R is light and the Motegi SP10 is always a good choice if you want a cheaper wheel that is close to OE weight.

Wheels for 2012 Toyota Prius c Two

 

Heres my plan when the snow gets to deep i'll drive my del-sol and just blast through the big nice person drifts just cause i don;t care and it worked before and it was fun

 

I just came across this thread. Why did you not tell me this before I bought my rims?? lol

 

LOL

Every third post by me focuses on tires and how upsizing kills mpg. I figured you knew.

 

I like fat tires, always have and always will. I even have big fat tires on my motorhome. Can remember the first set of fat tires for my 65 Mustang parked in the garage. That was in 1970. 42 years later, the car still has fat tires. I was well on my way to a set of fat tires when I bought the new rims for the C. People ask, "what kind of mileage?" I say"50". Can I still say that with fat tires? Hmmm. So, for now I have the skinny tires that came on this car mounted on my nice fat rims. Every friend I have knows I like fat tires. "Why you got skinny tires on the new car Dan?" Now, we will try to wear out these tires. I want a set that will rub my inner fenders when I brake and turn hard left or right. Will I have to say "45 mpg" when I do this? Hope not. It will happen. I will let you know how big fat 15 inch tires do on 7 inch rims. Life is good and the C carries us to Lambert Field this morning.
Ramblings by Dan, 58 yrs old Merry Christmas to All.

 

damn. i hate hubcaps and steelies. 2013 and still coming with them. guess im sticking with them for a while since upgrading is a no-no for mpg (the main reason i bought the car)

 

Volk has a 15" wheel from Japan thats 7.4lbs! and you can use the stock tires

 

i really like the setup! what did you finally go with? rims that the stock tires?

 

There are light weight rims you could purchase out there around 9-12 pounds each. Just keep them same size, if you go with bigger wheels, you get less mpg. Konig Helium as an example.

 

There are plenty of 15" aftermarket wheels you can use without killing fuel economy. Just stick with a 15" and choose a very fuel efficient tire.

 

The effects of wheel inertia are greatly overstated. If all the additional mass were added at the outside diameter of the tire (which it isn't) each lb added to a wheel would be the equivalent of 2 pounds added to the not rotating mass of the car. If you increase each wheel/tire combo by 5 lbs that is the equivalent of adding less than 40 lbs of mass to the non rotating part of the car. The drop in fuel economy is primarily from a difference in tire rolling resistance.

 

here's an article that discusses the low wheel weights and size of wheel advantages.

Wheel/Tire Size & Weight - Impacts on performance. (nice article and cool calculator) - N54tech.com | BMW N54 N55 135 335 535 Turbo Performance Forum

In short, if you keep the same diamter wheel/tire while reducing the weight about 4 lbs each, that would have a simualr result of reducing about 160lbs out of the car. Using 1 lbs of wheel/tire = 10lbs of total vehicle weight, from previous threads seems to add up per this article's refernce to a "date riding shotgon"

it also explains why folks here who moved to 16's and 17's see drops in MPG. Assuming the overall diamter of the tire/wheel combo is the same. When weight dispersion is moved closer to the perimeter or outside edge of the wheel, more energy is required to spin that object. Think about picking up a 15 lbs weight and rotate it while holding it in your hand. Now tie a 1 foot rope to that 15lbs weight and attempt to rotate it. It requires a lot more energy.

Why, well we may need a physics professor to explain, but one reason is the amount to distance the weight is required to travel through the air. It would take less energy to hold the weight with your hand, and have the rope spin around through the air, right? Hope this helps answer a lot of the questions on this topic.