steering response of 15inch wheel prius vs 17inch wheel

The 17 inch wheel equipped Prius supposedly has a different steering ratio. However, many ppl mount 17 inch oem wheels on cars which came with 15 inch wheels successfully.

The 17 inch tires have shorter sidewalls which flex much less, and have better response time to improve cornering and handling.

 

We took our first test drive in 15" model, second in 17" model (Can Touring). I felt much more at ease with the Touring, the steering felt more natural. Bought it the same day.

 

How is it possible for the car with 17" wheels to feel "more responsive," yet be less "sensitive to any input"?

 

I drive on 215/45r17 tires in the summer and 195/65r15 tires in the winter. Both are stock Prius sizes.

The tire wraps around the steel/alloy rim. There is more air between the rim and the ground in the 15" vs the 17" stock Prius tire. The more technical term is tire profile. The 15" tire has a bigger air cushion, so it will deform or push-in a bit every time you turn before the responsive force is felt by by the rim. It also means that the 15" is a more comfy ride because of the bigger air cushion because it will deform more every time you go over a bump.

Lastly, the 15" gets better fuel economy because it is lighter.

 

Try raising the tyre pressure of the 15" equipped car. I use 40 PSI front and 38 PSI rear. The ride will be slightly harsher but the steering a little tighter. In my opinion, the 35 PSI on the door placard is just too low.

 

I think you've nailed it. The models that come stick with 17" have a different steering feel. Like Siward, I swap over, from 17" to 15" every winter, the steering still feels solid, planted.

They should use that steering confugration on all models, my 2 cents. Only thing, turning radius is a bit bigger, and appreciably so, in compact parking lots.

 

I think so.

 

There are two EPS motors available. The 17" wheel OEM equipped cars get the "stronger" one. The 15" OEM equipped cars get the "weaker" one. As posted above the ratios are different, and perhaps that is why one is "stronger". According to information from Toyota. You -CAN- put the 17" wheels on the cars that came with 15" ones (the wheel tyre combo diameter is almost the same - set by using a lower profile tyre on the 17"). Whether it will eventually cause "problems" is debatable (and will be now that I've posted it). -Usually- a car manufacturer uses stronger parts only then they are needed. In this case it may be mainly because the "weaker" EPS might cause more effort from the driver, and we all know how lazy they can be.

The tyre patch is larger on the 17" wheel/tyre, resulting in higher forces required to actually -turn- it (while stopped). The 17" also should give higher braking force (quicker stops) and higher cornering forces, but also poorer mileage, due to higher drag.

There are -always- trade-offs!

As I implied in my earlier post, you can "tweak" the variables with things like tyre pressure and tyre brand/type, even in the same diameter wheel. Also larger diameter wheels tend to be heavier, unless you buy really nice (read expensive) ones like the Rays "Ecodrive" model intended for the Prius. I would -still- love of have a set of those, but what would I do with the nice OEM wheels?

 

So, technically, it wouldn't be smart for me to install the 17's on my car since my EPS motor isn't that strong? I've thought about putting the 17's on but wasn't sure. Don't want to break anything or burn anything up.

 

Lots of owners have swapped out the OEM 15" for 17", it'll clear, and I'd suspect steering feel about the same.

Personally, with our OEM being 17", I've thought about doing the opposite switch, for softer ride and better mpg. But I doubt I'll ever follow through, too much expense and hassle.

And ultimately I prefer to keep it stock.

 

I've switched out the 15s on some of my cars to 17s. Steering feel is the same at low speeds, more stable at higher speeds.

Best thing I've done for the cars

SM-N900P ?