[KlumzyDriver]

Wouldn't getting smaller 15" rims/tires then result in inaccuracies in calculating distance, speed, mpg? Maybe even introduce some inaccuracies in how the car computes the most efficient operation? To me, smaller wheels mean they have to rotate faster to go a given distance than a larger wheel would.

 

[ddemetra]

Wouldn't getting smaller 15" rims/tires then result in inaccuracies in calculating distance, speed, mpg? Maybe even introduce some inaccuracies in how the car computes the most efficient operation? To me, smaller wheels mean they have to rotate faster to go a given distance than a larger wheel would.

Good question.
I live in Canada, have minus sized all my winter tires for the last 10 years
Better performance as you can get narrower, more fuel efficient tires that drive better through deep snow, and saves money buying the rim and tire.
You can read about it here
https://info.kaltire.com/what-is-minus-sizing/


When you minus size, you reduce the outer diameter of the rim, but then increase the depth of the tire to compensate.
This way the outer tire diameter is constant, so none of your worries apply.


You can use a calculator such as here to view alternate tire sizes that keep the original outer diameter.
https://tiresize.com/calculator/


Fun stuff to learn.

 

[sleewa]

Wouldn't getting smaller 15" rims/tires then result in inaccuracies in calculating distance, speed, mpg? Maybe even introduce some inaccuracies in how the car computes the most efficient operation? To me, smaller wheels mean they have to rotate faster to go a given distance than a larger wheel would.

You can also check www.tirerack.com where they explain minus sizing - I've bought winter tires from them on 15" rims - just put them on my Insight today.

 

[Jc_vt]

about to do the same....which rims did you get?

You can also check www.tirerack.com where they explain minus sizing - I've bought winter tires from them on 15" rims - just put them on my Insight today.

 

[sleewa]

about to do the same....which rims did you get?

I bought some alloy Enkei's that were being closed out - they're no longer available. I bought these in early September, and just looked now at Tire Rack and saw that the steel wheels are sold out for the season

 

[yecam]

Have you considered down sizing the wheels or conversely up sizing the tires. Here is just one link for the Touring but the site also has details for the other 2019 Insights.



https://tiresize.com/tires/Honda/Insight/2019/Touring/


There are a number of potential benefits for downsizing the wheels and mounting the appropriate compatible tire that gives you an identical circumference with a very small percentage. These include better winter road grip, possible savings in total weight leading to better MPG and possible savings in price. You might also find better selection in tires.


The better road grip idea comes from using thinner and higher tires that put more weight on a slightly smaller patch of road, thereby obtaining better friction when there is a bit of ice or slush under the car. I am an advocate of snow tires rather than using those all season. all weather compromises even where you do not have all that much snow in the winter. Once the outside temperature falls below +7 degrees Celsius you really want to be using rubber that works when it is cold. On the other hand, when things warm up you must go back to the summer option when snow tires lose their road grip advantage.



From experience I can state that the downsizing option saved me a bundle when I was able to use the one year old winter tires from my 2014 CRV on my 2016 Hyundai Tuscon. This has been traded in for my Insight which comes with snow tires mounted on steel wheels. You do not want to be using alloy wheels in salty snow unless you like corrosion effects where the roads are treated with salt. Steel wheels are heavier than alloy wheels but downsizing could help in that area. They are also much less expensive and once they get covered in salt spray look just like white alloy wheels that need washing

 

[andrew28]

With the help of TireRack I was able to find alternate tire sizes that will fit our Honda Insight. Just make sure the load index is equal or greater than what Honda recommends. LX/EX is 93 and Touring is 91. These alternate tire sizes allows us more choice in tire options. For example, I have been eyeing the Michelin CrossClimate+ which does not come in 215/55/16 size but they fit the alternate size 205/60/16 for the 16" EX wheels.

 

[Wifey'sInsight]

With the help of TireRack I was able to find alternate tire sizes that will fit our Honda Insight. Just make sure the load index is equal or greater than what Honda recommends. LX/EX is 93 and Touring is 91. These alternate tire sizes allows us more choice in tire options. For example, I have been eyeing the Michelin CrossClimate+ which does not come in 215/55/16 size but they fit the alternate size 205/60/16 for the 16" EX wheels.

Just wanted to point out that a load index of 91, is sufficient for all trims. Most likely the OEM tire choice for the lx/ex just happened to be a higher load index rating, but seeing as the Touring is heavier, it can safely be extrapolated that a load index of 91 is safe for our cars as well

 

[andrew28]

Just wanted to point out that a load index of 91, is sufficient for all trims. Most likely the OEM tire choice for the lx/ex just happened to be a higher load index rating, but seeing as the Touring is heavier, it can safely be extrapolated that a load index of 91 is safe for our cars as well

I figure it was alright with a load index of 91 but some places like Costco would not install a tire with a load index lower than what is on the door jam sticker.

 

[Wifey'sInsight]

I figure it was alright with a load index of 91 but some places like Costco would not install a tire with a load index lower than what is on the door jam sticker.

This is the issue with doing all of my own labor; I always hate it when I have to rely on a shop for them to refuse work for "insurance" purposes, even though most make you sign some type of release in the work order. Just for laughs, I refreshed my memory of the tire loads.

Touring- 91 = 1356lbs x4 = 5,424
EX/LX- 93 = 1433 lbs x4 = 5,732

Which further supports my theory that Honda went with Stock tires for OEM choices, so that would describe the difference in load rating, as the Touring is 80lbs heavier, but the LX/EX tires are rated for 308 more lbs.

I ran into the same type of issue with my Colorado. I swapped out the stock wheels (for my trim) for the larger wheel/tire combo of the "off-road" trim. I was a few hours from home, got a nail in a tire, and when they started hem-hawing over not wanting to repair the tire, I asked if I could just buy another tire. They refused to sell it to me, because it was a different spec than the "OEM" spec. Long story short, I slipped a tech a $20 bill, and 15 minutes later my tire was plugged.