ESP disabled on my s550 need some advice
12-17-2011, 01:48 AM
#26
Senior Member
rominl FYI meaning of diameter is the size of the inner circle from point to point using a straight line, which in this case it is 20 inches, the first three digits/number written on the first part of the measurement is the width of the tread. his tire have the same front and rear diameter which is 20. (255/35/20 and 275/35/20) really don;t know where you got the idea of interpreting the size.
first three digit represent the width of the thread, the second set of number is the height of the tire wall and the last two digit is the size/diameter of the inner hole of the tire/mag-wheel size.
first three digit represent the width of the thread, the second set of number is the height of the tire wall and the last two digit is the size/diameter of the inner hole of the tire/mag-wheel size.
here's the math
255/35/20. side wall height = 255mm * 0.35 = 89.25mm = 3.51". both ends = 3.51" x 2 = 7.03". plus 20" rim = 27.03"
275/35/20. side wall height = 275mm * 0.35 = 96.25mm = 3.79". both ends = 3.79" x 2 = 7.58". plus 20" rim = 27.58"
difference = 27.58" - 27.03" = 0.55"
the car won't care what the diameter of the RIM is. diameter of of the overall wheel (rim + tire) is what determines the full rotation and that's what cause a difference in the number of rotation front and rear, indicating to the car that there is a "slip"
cool_lagoon, go check on the actual information before giving wrong information to other readers which might potentially damage their vehicles
http://en.wikipedia.org/wiki/Tire_code (Tire geometry section)
Last edited by rominl; 12-17-2011 at 01:59 AM.
12-17-2011, 04:28 AM
#27
Super Member
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10 speed bicycle
i know quite a bit about tires and i am very well aware of what the numbers mean on the tires. the first number is the width of the tire in mm that's correct. however what you failed to realize is that the second number is actually the aspect RATIO of the sidewall height, which actually means it's a PERCENTAGE of the width. and then the third number is the diameter of the wheel that the tire(s) fit on in inches.
here's the math
255/35/20. side wall height = 255mm * 0.35 = 89.25mm = 3.51". both ends = 3.51" x 2 = 7.03". plus 20" rim = 27.03"
275/35/20. side wall height = 275mm * 0.35 = 96.25mm = 3.79". both ends = 3.79" x 2 = 7.58". plus 20" rim = 27.58"
difference = 27.58" - 27.03" = 0.55"
the car won't care what the diameter of the RIM is. diameter of of the overall wheel (rim + tire) is what determines the full rotation and that's what cause a difference in the number of rotation front and rear, indicating to the car that there is a "slip"
cool_lagoon, go check on the actual information before giving wrong information to other readers which might potentially damage their vehicles
http://en.wikipedia.org/wiki/Tire_code (Tire geometry section)
here's the math
255/35/20. side wall height = 255mm * 0.35 = 89.25mm = 3.51". both ends = 3.51" x 2 = 7.03". plus 20" rim = 27.03"
275/35/20. side wall height = 275mm * 0.35 = 96.25mm = 3.79". both ends = 3.79" x 2 = 7.58". plus 20" rim = 27.58"
difference = 27.58" - 27.03" = 0.55"
the car won't care what the diameter of the RIM is. diameter of of the overall wheel (rim + tire) is what determines the full rotation and that's what cause a difference in the number of rotation front and rear, indicating to the car that there is a "slip"
cool_lagoon, go check on the actual information before giving wrong information to other readers which might potentially damage their vehicles
http://en.wikipedia.org/wiki/Tire_code (Tire geometry section)
12-17-2011, 03:17 PM
#28
Super Member
Another possible cause
I received the message a few times about ESP being inoperative on my vehicle.
Dealer believes it was caused by low state of charge for the battery in the trunk. I had only driven very short distances for a couple of weeks and the dealer believes this was not sufficient to recharge the battery.
They suggested that I charge this battery in my garage with an external charger if this happens again and see if it cures the problem. The dealer recommended that I purchase a charger from an auto parts store and NOT from the dealer since the official Mercedes battery charger they sell is very expensive.
Dealer believes it was caused by low state of charge for the battery in the trunk. I had only driven very short distances for a couple of weeks and the dealer believes this was not sufficient to recharge the battery.
They suggested that I charge this battery in my garage with an external charger if this happens again and see if it cures the problem. The dealer recommended that I purchase a charger from an auto parts store and NOT from the dealer since the official Mercedes battery charger they sell is very expensive.
