Anyone fit narrower tires for improved fuel economy?

[Joesonic]

Hi everyone,

I'm not too happy with the overall fuel economy between my 2019 Sonic LT and 2020 Sonic RS. Both cars are 1.4L with automatic. My RS is rated at 2mpg LESS on the highway than my old 2019 LT. Other than the decklid spoiler, the only big difference I can think of is the size of the stock tires; 195/65R-15 and 205/55R-16, respectively.

I'll need to replace tires soon, as I just ticked over 28k miles and I will need to make a decision for replacement. I was thinking going with a narrower tire for less contact patch on the road and less rotating mass. Which, in theory, should translate into slightly higher fuel economy, especially on the highway.

I was looking at the 185/60R16 (same size used in the Toyota Yaris which has a similar curb weight as the Sonic). The 185/60R-16 would only increase revolutions slightly per mile. Other than throwing the speedometer off by 1/2%, are there any other downsides? Total load carrying capacity maybe?



Anyone have experience with this? Will the tire installer give me a hassle?

Thanks for the help!

 

[macdiesel]

As long as the speed rating and load capacity are the same or better you should be fine. What tires are you currently running? You might be able to achieve what you’re looking for with tires alone. When I went to a michelin premier a/s my mpg’s increased. Road noise decreased.

 

[Joesonic]

Thanks, macdiesel. Unfortunately, I had to get new tires, and the dealer wouldn't install the narrower size tires. The load rating was the problem. The 185-60R-16 tires had a load rating of 86H - 1,168lbs which is 188lbs less than the 205-55R-16, 91H - 1,356lbs. My stock tires failed inspection, and I didn't have time to shop around. So, I was stuck on the spot to purchase 4 new tires. The dealer wouldn't install tires with almost 800lbs less load rating, worrying that I might overload the car. It's just me and some weekly groceries!

Anyway, I tried to get the Goodyear Assurance FuelMax tires, as I have had good luck improving my mileage with them in the past. But they wanted $200/tire.

They sold me Kelly Edge Touring A/S tires size 205-55R-16. They have a 700/treadwear rating, A+A Traction + Temperature rating, they are 91V rated to 149mph and carry a 45k mileage warranty. As a bonus, the service writer let me know that Kelly tires are manufactured by Goodyear! They were $90/less per tire, it was a no brainer. I'm on a budget.

I didn't even have 30k miles on the stock Hankook Optimo tires and they were worn down to the tread bars.
Those Hankook Optimos did great in the dry, wet, snow and handled phenomenally, but their wear characteristics left much to be desired. The last time I had tires wear out before 30k miles were a set of Cooper Cobras nearly 30 years ago!

The other service writer told me that the Hankook Optimo 712 was custom manufactured to Chevrolet's specification to be installed at the factory w/out the mileage warranty. According to him, you can't buy them aftermarket. Only the Optimo 714 is available for purchase, which just so happens to carry a mileage warranty...