Frank gets new winter boots (pics)
12-09-2013, 12:21 PM
#51
Junior Member
Join Date: Sep 2013
Location: Long Island, New York
Posts: 32
Likes: 0
Received 0 Likes
on
0 Posts
2014 ML63, PORSCHE 997 Turbo Cabriolet, Ferrari F430, Durango HEMI, 93 HD FLSTN, 04 HD FLHTCSE
Hear what you're saying ; small chance it could be the lowering as you say/ change in camber. Not sure what speeds you're feeling this but maybe try raising the vehicle, see if it makes a difference?
The Scorpion "Snow & Ice" has large tred blocks which can add to the squirminess you describe. From Pirelli RE: "WINTER"- "Progressive and responsive dry handling thanks to new rounder mould profile".. Some difference/ degree of a handling deficit is expected going to your snow & ice compared to the summer tires in higher temps but they shouldn't feel unsafe.
RE: Sipes - The Scorpion Winter TUV test where it won "best in class" was on a 255 width tire. The new compound has a higher % of silica... Just to mention - Not sure if you were looking at a "Winter" with just 3 sipes but all sizes on "Winter" above 255 have 5.
http://www.pirelli.com/mediaObject/p...ION_WINTER.PDF
Lowering pressure can also make this 'squirminess' worse. You're allowing the sidewall to flex more + the softer tire compound + tall tred blocks... You want to increase pressure on winter tires but I know what you mean, "46 psi" is high. If I don't tell the dealer to leave my tire pressures, they always increase pressures for a vehicle that is fully loaded (passengers plus luggage) pressures.... On my 997 Turbo the dealer will put in 44psi, as soon as I drive off it feels like I'm driving on rocks. If you dig far enough into the Porsche's owners manual, it will tell you w/ out passengers plus luggage 33psi fronts & 39psi rears are recommended for "driving comfort". I've looked quickly in the ML63's manual but didn't find a similar "comfort" psi .... The 46psi you mention is probably what is on the inside drivers door on our ML63's for the 21" wheels 295.
Your current 35 psi sounds slightly low though, using my best guesstimate I set my Scorpion Winters at 40 psi on a digital gauge before having the sensors pick up the new wheels/set. But maybe others can chime in on winter tire psi.
The Scorpion "Snow & Ice" has large tred blocks which can add to the squirminess you describe. From Pirelli RE: "WINTER"- "Progressive and responsive dry handling thanks to new rounder mould profile".. Some difference/ degree of a handling deficit is expected going to your snow & ice compared to the summer tires in higher temps but they shouldn't feel unsafe.
RE: Sipes - The Scorpion Winter TUV test where it won "best in class" was on a 255 width tire. The new compound has a higher % of silica... Just to mention - Not sure if you were looking at a "Winter" with just 3 sipes but all sizes on "Winter" above 255 have 5.
http://www.pirelli.com/mediaObject/p...ION_WINTER.PDF
Lowering pressure can also make this 'squirminess' worse. You're allowing the sidewall to flex more + the softer tire compound + tall tred blocks... You want to increase pressure on winter tires but I know what you mean, "46 psi" is high. If I don't tell the dealer to leave my tire pressures, they always increase pressures for a vehicle that is fully loaded (passengers plus luggage) pressures.... On my 997 Turbo the dealer will put in 44psi, as soon as I drive off it feels like I'm driving on rocks. If you dig far enough into the Porsche's owners manual, it will tell you w/ out passengers plus luggage 33psi fronts & 39psi rears are recommended for "driving comfort". I've looked quickly in the ML63's manual but didn't find a similar "comfort" psi .... The 46psi you mention is probably what is on the inside drivers door on our ML63's for the 21" wheels 295.
Your current 35 psi sounds slightly low though, using my best guesstimate I set my Scorpion Winters at 40 psi on a digital gauge before having the sensors pick up the new wheels/set. But maybe others can chime in on winter tire psi.
12-09-2013, 04:17 PM
#52
MBWorld Fanatic!
Thread Starter
Join Date: Aug 2013
Location: Alberta, Canada
Posts: 1,267
Likes: 0
Received 52 Likes
on
46 Posts
'18 GLE63S AMG /'19 PORSCHE TURBO S / '09 CORVETTE ZR1 /'14 LEXUS RX350/'16 RAV4 Ltd
I doubt it's the t/p...it would do it always..and I doubt it's the body height..good try but not sure what effect would that have on wheel/tire attitude.
It certainly appears to be a condition of the tire to icy surface and contributed by alignment, tire tendency or both..
Luckily I don't have to endure this condition on a regular basis. I'd put my money on the cause being camber/castor etc...we'll see if yours has the same tendencies...interesting tho
It certainly appears to be a condition of the tire to icy surface and contributed by alignment, tire tendency or both..
Luckily I don't have to endure this condition on a regular basis. I'd put my money on the cause being camber/castor etc...we'll see if yours has the same tendencies...interesting tho
05-17-2015, 02:12 PM
#53
Newbie
Join Date: May 2015
Posts: 11
Likes: 0
Received 0 Likes
on
0 Posts
2012 ML350
