If you have a 235 60 15 as the factory spec, will it make much difference going for a 225 60 15 (rims would remain the same)? The price of a 235 is £150, the price of a 225 is £75. I will be changing the whole set, so all 4 would be 225's. I know that the speedo will be slightly off by approx 1mph, but wondering if any further thought should go into it?
Looked into the load rating, the 235's are 750kg, the 225's would be 710kg's, so 40 kg per tyre / 160kg overall difference.
Also in regards to the speed rating, the ones on there are 112mph whereas the 225's would be 168mph.
Ok did some thinking in regards to the load. The curb weight is 3530 US pounds. This translates to 1,601.19Kg's. Distribution is 57% front, 43% rear. So the front ones would see 456.33 kg's each, the rear would see 344.25kg each. With the front carrying the most weight so they would be the ones to scrutinise, the original tyres would have a margin of 296kg, the 225's would have a margin of 276kg. I would assume that this margin would still be acceptable with the 225's? I have been dis-generous with the curb weight, as it's estimated at 1,569.5 to 1,601, so i went with the heaviest weight on the calculations.
There will also be a smaller contact patch area of 1 cm per tyre / 4cm overall. As i'm not driving it on the edge, i imagine this will make an unnoticeable difference too?
I wouldn't usually give it this much thought if it was £10 / £20 difference, but a Pirelli tyre is £200, a cheaper one is still £150 for a 235, but the 225 continentals i can get are £80 so it's a huge difference as it's 4 tyres... £800 vs. £320 for a difference of 20kg's and 1cm per tyre. The Continentals have a higher grip, speed (112 vs 168 mph) and efficiency rating too.
Cheers!
