205/50/15 vs 195/55/14 tyre comparison

mitch_f1 · Postby **mitch_f1** » Wed Jul 28, 2010 7:09 pm

So my 2nd hand dunlops are coming to an end, and I need to start looking for replacements. The tyres were by far the wrong size at 205/60/15 so I have to start from scratch pretty much. Initially I was looking at 205/50/15 but the current wheels I have I think are quite heavy (not sure though; has anyone weighed the old 6UL immitation Mania wheels - with tyres they are 16.8kg a corner, which is quite heavy I think, as the tyres shouldnt weigh more than 10kg), so I am just kind of half looking for new wheels. But I started thinking, my Type Cs are the 2nd lightest wheels ever made (to my knowledge), so why not use them, especially being that apparently no one wants to buy them. Only problem is they are 14x6" which isn't massive. The maximum size tyre I would be able to fit would be a 195, and even then that would be a bit of a stretch.

So, my question is this. Would going for the smaller SSRs in favour of their significantly lower weight (hence better acceleration, faster turn-in etc), over the larger and heavier 15" wheels be negated by the fact that they are 195/55/14 vs a 205/50/15 and hence have less mid corner grip.

rascal · Postby **rascal** » Wed Jul 28, 2010 11:16 pm

mitch_f1 wrote:So, my question is this. Would going for the smaller SSRs in favour of their significantly lower weight (hence better acceleration, faster turn-in etc), over the larger and heavier 15" wheels be negated by the fact that they are 195/55/14 vs a 205/50/15 and hence have less mid corner grip.

Assuming the same tyre/compound for both then the much lighter weight of the SSRs would far outweigh a minimal reduction in tread width...

mitch_f1 · Postby **mitch_f1** » Wed Jul 28, 2010 11:23 pm

would the side wall flex difference (in terms of the less amount of stretch) make a difference in terms of turn in?

rascal · Postby **rascal** » Thu Jul 29, 2010 10:13 am

mitch_f1 wrote:would the side wall flex difference (in terms of the less amount of stretch) make a difference in terms of turn in?

Technically yes, but realistically probably not enough to notice. You are only talking a 5% difference in sidewall height, which might translate to a 1 or 2% difference in cornering speed. (So you could 'only' carry 71kmh through a corner vs 72kmh with the lower profile tyres..)

Dropping kilos off the rotation weight would make waay more difference than the above..

mitch_f1 · Postby **mitch_f1** » Thu Jul 29, 2010 11:37 am

I was more thinking about the amount of stretch going on; I would have thought to put a 205 on a 7" rim with a 50 prfile tyre there would be more stretch, and hence more ridgiditiy and less flex, than putting a 195 on a 6" rim with a 55 pofile, which will have less stretch, and hence more bulge, and more flex.

rascal · Postby **rascal** » Thu Jul 29, 2010 1:13 pm

I'd imagine the same answer as above.
Ignoring 14" vs 15" and assuming identical tyre, a 195 or 205 would perform better on a 7" rim than on a 6" rim, though again probably not enough difference to matter.

And definitely not enough to justify running a much heavier rim..

Robbo107672 · Postby **Robbo107672** » Thu Jul 29, 2010 1:24 pm

I have just fitted Dunlop DZZ1 Star Spec 195/60/14's to 14x6 solid seven spoke wheels, and they are a fantastic tyre for $185 per corner with club discount. Given that they make these in 185 & 195 14's I wouldn't go past it if you have the rims already. 185's go well on the 5.5 inch rims and 195 fits nice on the 6" wide rims. There is only 2% difference in speed on the gps between the two, so wouldn't worry about that. The 195's on my NA6 are spot on, ie. 100kph on speedo = 100 kph on GPS.
Rob.