I was interested in the weight difference myself tbh and it was part of the reason for changing as the old 18" wheels seemed really heavy! Whilst swapping them over I tried to feel for weight difference but there wasnt much in it at all... I wasn't anal enough to get the bathroom scales out though!!!![]()
I checked out all the tyre ratings and the new tyres are superior to or equivalent to the old ones in every aspect so I'm assuming the slightly softer feeling in the corners is due to the small increase in profile size of the tyre... It's certainly enough to make an improvement to the ride quality generally on rougher surfaces though (and over bumps!) which was another reason for the swap!
Thanks man... Hey I was looking at the tyres again & meant to ask about this max pressure thing- On one part it says "never inflate beyond 40psi ... when seating beads" (Or something very similar) and on the other side it says "max load 1730 at 49psi" (IIRC) - So is the max pressure 40 or 49psi???
You finfd there's a lot more info on the sidewall than it first appears when you take a good look at it!!!![]()
Well, since he's now got more sidewall using 17's instead of 18's like he had it'd negatively effect cornering. The weight of the wheels shouldn't do too much to the corner capabilities vs. what the difference in tires is doing. His 18's were reps as well, so they might've been as heavy or heavier.
Really just think the difference in cornering capability he's experiencing is due to the taller & different make of sidewall on the 17's vs. what he had on the 18's.
Ah, so max psi is 49, not 40. That sounds more like it. Go ahead an try 33f/38r and see how that is.
Cosmos Black/Black 1995 540iA M-Sport
BMW Individual Exclusive Edition, 1 of 65 total, 9/25/95 Build
The 40psi when seating bead is a lawyer-based statement. Can you imagine the lawsuit that brought this mandatory statement? Some yahoo pumping endless pressure in a 'dry' tire trying to seat the bead, then the bead releasing past its seat on the rim edge and possibly sending parts of the tire into the yahoo...hence the 'do not exceed' pressure statement.
49psi is the max 'working' pressure. Given the couple psi rise as the tire temps climb, the tire may see low to mid 50psi in normal use...
Hope this makes some sense,
Brian
I think mine are at 33 front and 38 rear. Running Michelin PS2's 235/45/17.
Cosmos Black/Black 1995 540iA M-Sport
BMW Individual Exclusive Edition, 1 of 65 total, 9/25/95 Build