Installed Lexus CT200h 17" wheels and 205/50/17 tires

I recently decided I just couldn't live with the OE 15" wheels anymore. I also couldn't bring myself to buy aftermarket 15s. I know the change will negatively affect my mpg but I can accept that for the better looks, handling, and magin of safety. The fact the 2012 OE black wheels are in demand makes the trade easier to stomach.

I chose the Lexus CT200h wheels because they will maintain an OE look and the offset is perfect at +45mm. The weight is not good at 24-25lbs but Five owners seem to do well enough on the OE 17s which weigh about the same. My goal was to try and reduce the mpg impact as much as possible yet stay cheap. So keeping the high offset will keep the wheel tucked in the wheel well and out of the air stream. I also chose a new tire by Continental called the PureContact with EcoPlus. It is a totally new grand touring tire that is affordable ($137/ea) and long lasting (70,000 miles). It is designed to be better than other OE grand touring tires (Primacy MXV4 and Turanza) yet last longer and be more fuel efficient than UHP tires on the market. I chose it in a 205/50/17 so as to maintain the original tire diameter of the OE 15s (195/65/15). This will also help to reduce wheel well gap in hopes that I wouldn't have to lower the car. It should also increase ride comfort.

Here are a couple of bad cell phone pics. Please excuse the dirt. I just got back from Tahoe and have not washed the car in weeks.







Side shot to show offset. They sit somewhere between the Five wheels (+50mm) and the Performance Plus wheels (+43mm)



For comparison here is the same car with a 215/45/17 tire with lots of tread still on them. The gap is not drastically different but you can tell the 215/45/17 has more gap.

 

Thanks!

They are directional but you can't change anything about them so they are not left/biased. So the direction is reversed on the wheels on the passenger side. It's like that on the CT as well.

 

So far this is the best I could find. Interestingly, the just barely beat the Primacy MXV4 in the V-rated tire class and were just barely beat by the MXV4 is the H-rated size. They are an XL (Extra Load) tire in this size as opposed to the S (standard) in the 215/45/17 size so these are rated for much higher loads.

From Consumer Reports:

 

Thanks Kevin. That means a lot coming from a clean modder like yourself. I think the 205/50/17 is THE size to go with when upsizing wheels if you don't plan to lower the car. The wheel well gap is still pretty large but the tires look like a better fit than the 215/45/17 which is approx. .4" shorter (total diameter).

 

I originally considered the Tridents as well but it's harder to find them used and they were too dark for what I wanted to do. The offset is too low as well so they will stick out too much.

 

I think they would have a hard time proving my tire height was the cause for any failed part considering these tires are the same size as the OE 15s.

 

Like Kevin said, you don't have to reprogram anything BUT I would suggest verifying the accuracy of your speedometer with the new tires. This way you'll know the exact speed you are traveling. Perform the test with a quality GPS unit or a cell phone app when you have good reception. In stock form the Prius speedo reads about 1.5 to 2mph faster than you are really traveling.the new tires could change this slightly because they are shorter than the OE 15s (24.7" vs. 25").

 

So far as of this morning I am down between 6-7mpg when compared to my usual morning commute using no hypermiling techniques except driving slow at 60mph. I usually get 52-53mpg when I just use CC and drive. This morning with similar temps I got 45.8mpg.

 

I pumped up the tires to 42/40 psi yesterday at around 75F. I drove to work this morning at 60F and the tires felt pretty stiff. They were stiffer and louder than the Energy Saver A/S was at 47psi. The car felt more stable but I don't like the ride so far. I will lower the pressure to 38/36 for a while until they break in. They felt pretty soft when I left the tire center at 33psi. They stick pretty well for only having 30 or so miles on them! Being an XL tire they are likely to feel stiffer than a regular SL tire which we are used to.

Also of note, my speedometer read exactly the same as my GPS readings. 60mph on the dash was 60mph on the GPS. Scangauge II still read 2mph lower. So part of the mpg difference can be attributed to driving 2mph faster than normal. With the OE 15s, AVID Ascend 15s and Energy Saver A/S 15s the speedo read 1.5-2mph too fast.

 

I'm a little concerned as well because the Primacy MXM4 wasn't this stiff until you got over 45psi, even when new. The MXM4 was only rated at an 87SL Load Index though compared to 93XL on the PureContact. XL tires have more material between the sidewall and tread patch which allows them to carry higher loads and often makes the tire better for steering feel and handling by reducing deformation. It reduces comfort, however.

By the end of the week I'll have a few hundred miles on them and I will try to hypermile to work on Monday and see how it goes. I was able to get 48mpg+ with the 17" MXM4s back in April? when I tried to hypermile them. The MXM4 had a lot more miles on them though. I'll look back through that old thread and try to compare numbers. So far though, the MXM4 is more comfortable and quieter. The Pure Contact looks nicer and steering response is better. With the MXM4 (215/45/17) the speedo read 1mph too fast.