Testing MPG with 17s vs. 15s

I didn't mean to. I swear.

It would be similar to what I have been doing so re-read my postings. I had the same 17s on my GenII and my GenIII. The 17s were taller than my GenII tires but shorter than my GenIII tires. Either way the ride was rougher but they may not be too different than the hydroedge which is known for being a bit rough. Expect the gas mileage to tank on the Prius, however. The GenII gets hit hard.

If you do it then I expect a full report after the first tank on both cars.

 

I figure if I am going to stick with ugly uninspiring 15s then I might as well get the full benefit of the smaller tire so I traded in my Ascends for a set of Energy Saver A/S today. For the cost of installation, the guys at Yokohama and America's Tire in Woodland, hooked me up with a new set of shoes. My commute route tomorrow will be a mess and I have a 110lb generator in the hatch so no testing tomorrow. I have to get my oil changed and alignment checked to so I'll wait for all of this to settle out before I start testing again. I will say that at 35/33psi these Energy Savers are like riding on air they are so smooth. Tread depth is just shy of 10/32. I traded my Ascends in with the same tread after 10,000miles of driving. lol

 

I just make sure I note the temperature and wind during shorter segments of a tank and if I know those variables will change then I stop logging for that portion of the tank and reset the trip meter and start again with those changed parameters in mind. It's tough unless you regularly do long trips like I do. I can rack up 500+ miles in a week with just my commute and a side trip.

I'm pretty sure you will observe an obvious trend as soon as you switch the wheels as long as the weather doesn't change drastically.

 

You're such a bad influence! Haha

 

You have plenty of miles so that won't be a problem. You should notice the difference right away.

 

Do it! 17s are great if you don't mind the negatives I've listed. They make the car feel more solid and they look great.

 

I just swapped out my Energy Saver A/S 195/65/15 tires for a set of Continental PureContact with EcoPlus 205/50/17 tires on CT200h wheels and observed an instant 6-8mpg drop. The tires are brand new and need to be broken in but this is very similar to the drop I observed with the Primacy MXM4 215/45/17 and Centerline RPM wheels. It should be noted that both 17" tires weigh the same but my Centerline wheels were approx. 9lbs/ea. lighter than the CT200h wheels! The Primacys were well broken in too. If those damn Energy Saver A/S tires were never invented then running 17s wouldn't feel like such a bad decision. LOL

 

Interestingly, I am now running a set of 205/50/17 tires with a revs per mile of 828 and the speedo overread is now gone. That shouldn't happen as this tire is supposed to be the same size as the OE 15" tire. I need to do more research on deflection/deformation to see what is going on.