m6rk wrote: ↑Tue Aug 25, 2020 6:41 am
After a long investigation and comparison period, last Saturday I've finally bought new set of tires for my i3s!
I had no concerns about the tires when I bought my former EV, i3 '14. I tested the car and came into conclusion that the tires compensate their slim dimensions with a stickier compound they've got. For me, handling & braking performance is much more important than longevity. I would rather be safe during 30k km. than having mediocre handling for 40k km.
Now that I switched to i3s '18 my tire options became much more slimmer with 20" wheels... I thought. The original tires are really hard to find & very expensive. I made many technical readings on tire specs & dimensions online and finally I decided to play with tire dimensions on my i3s.
Long story short, I bought one set of "Goodyear Efficient Grip Performance" tires, 195/55 R20 (My first choice was Nokian Wetproof but they were out of stock). At the rear, only the sidewall changed to 55 from 50. At the front, only the thread part changed to 195 from 175. Overall diameters increased to 723 mm. from 703 mm.
The tires are perfectly fitted to the car. I am currently in evaluation period but my estimations after this change are:
- The acceleration, the range and the responsiveness will be a bit decreased.
- Top speed on GPS, the handling/braking performance, the comfort will be a bit increased.
Regarding speed, I mean the difference between the GPS speed value and the speedometer value will change. For ex: if it was showing "100kph @speedometer => 97 kph @GPS" before, then it will show "100kph @speedometer => 100 kph @GPS" now (which is currently the exact case). That means also the range data will decrease even if the tires have exactly the same characteristics with the original set! It is just because the car will cover more range then it shows when we look at GPS data. So, when comparing the range difference between original tires and current tires, we have to take this into account.
Once you opt to use 195/55 R20 on all 4 wheels you have plenty of options for i3s: Nokian Wetproof, Goodyear Effigrip, Michelin Primacy, Conti Eco Contact, Pirelli P7, Uniroyal, Hankook etc...
As you probably know the front wheel is narrower than the rear wheel, 5.5J & 6J respectively. 195 is the maximum width compatible with 5.5J wheels, so nothing to worry about that.
Strangely, there is much less option of summer tires for 18" & 19" wheels at 195 or less width.
Since very few i3 owners do more than 15k km per year and some of them -like me- have also a set of winter tires, 4-5 years of usage seems to be acceptable. Using the same tire set longer than 5 years is a bit risky, since the tire compound will certainly be affected by the environment (UV, temperature etc.)