Repair-It

Make
Vehicle
Symbols/Codes
Aston Martin
Some Vehicles
A4A
AMS
AM2
AM8
AM9
AMR
AMX
Audi
Some Vehicles
A
AO
RO1
RO2
AOE (Reduced-Range Extended Mobility Tire)
Bentley
Some Vehicles
"B" in a circle
B
B1
BC
BL
BMW
Some Vehicles
5-Pointed Star Symbol
Chrysler
Some Dodge Vipers
C1
Ferrari
Some Vehicles
F
K-1
K-2
General Motors
All Vehicles
TPC SPEC (Tire Performance Criteria Specification)
TPC SPEC 1156 M+S (All Season Tires)
TPC SPEC 1156 (Non All Season Tires)
Honda
Acura NSX
H-0 (H-Zero)
H-1 (H-One)
Hyundai
Some Vehicles
H
Jaguar
Some Vehicles
J
"J" in a circle
Lamborghini
Some Vehicles
L
Lotus
Some Vehicles
LTS
Maserati
Some Vehicles
MGT
McLaren
All Vehicles
MC
MC1
Mercedes
Some Vehicles
MO
MO1
MOE (Reduced-Range Extended Mobility Tire)
Mini
Some Vehicles
5-Pointed Star Symbol
Porsche
All Vehicles
N-0 (N-Zero)
N-1 (N-One)
N-2 (N-Two)
N-3 (N-Three)
N-4 (N-Four)
N-5 (N-Five)
N-6 (N-Six)
Volkswagen
Some Vehicles
A
VO

The numerical escalation of Porsche N-Spec tires reflect either enhancements to the previous generation of the same tire model, or a change in the design specifications of a tire model used on a current Porsche vehicle to better complement the needs of a new Porsche vehicle.

Like the motorsports tires they have evolved from, all Extreme Performance Summer performance category tires feature constructions and compounds that have been tuned to maximize traction and performance within a range of warm-to-hot ambient temperatures. Therefore, unlike less highly tuned tires, these types of tires must only be operated in and stored at temperatures consistent with their thoroughbred characteristics.

In addition to normal tire storage recommendations, Extreme Performance Summer performance category tires require supplementary storage procedures be followed to prevent tire compound cracking due to exposure to cold temperatures.

While these recommendations are general guidelines offered by Tire Rack, selected tire manufacturers may have additional specific recommendations applicable to their tires. Follow the tire manufacturer's recommendations whenever available.

It is not recommended to drive on these types of tires at temperatures below 40 degrees F (5 degrees C).

It is recommended these types of tires be stored indoors at temperatures maintained at above 20 degrees F (-7 degrees C) when not in use.

Tires accidentally exposed to temperatures of 20 degrees F (-7 degrees C) or lower must be permitted to gradually return to temperatures of at least 40 degrees F (5 degrees C) for at least 24 hours before they are flexed by adjusting inflation pressures, mounting them on wheels, or using them to support, roll or drive a vehicle.

In order to allow gradual, uniform and thorough increase in tire temperature, these types of tires should be protected from direct sources of intense heat as they warm up. Do not apply localized heat, blow heated air directly on them, nor place them near a heat source.

Always inspect tires before use after storage periods.

While compound cracking is not a warrantable condition because it occurs as the result of improper use or storage, tires exhibiting compound cracking must be replaced.

Whether you blame it on climate change, a polar vortex or what seems to be the beginning of the next ice age, there's no doubt recent weather patterns have exposed many drivers to freezing temperatures and wintery driving conditions. In anticipation of the next time Mother Nature extends her cold reach, drivers with vehicles equipped with summer performance tires need to know those tires are not designed for near- or below-freezing temperatures on clear roads, nor in slush, snow and ice.

When faced with near- and below-freezing temperatures, drivers should leave their summer performance tire-equipped vehicle at home and drive a vehicle equipped with all-season or winter tires.

Summer performance tires feature tread compounds engineered to provide traction in warm to hot ambient temperatures. They were never intended to experience near- and below-freezing temperatures, nor the wintry driving conditions that often accompany them.

As ambient temperatures get colder, typically in the 40-45° Fahrenheit range, summer performance tires lose a noticeable percentage of traction as their tread compound rubber properties change from a pliable elastic to inflexible plastic. The tire industry uses the term "glass transition" to describe the temperature where a summer performance tire's grip/slip performance changes dramatically. This means the summer performance tires that provide predictable traction in warm to hot conditions will be found to be very challenging to drive in cold to freezing temperatures. This is especially true when the tires first begin to be driven or if the driver aggressively applies gas pedal pressure with today's turbocharged fours or high-torque sixes and eights. Fortunately, glass transition is a reversible condition that allows the tires' normal traction to return as the ambient temperatures climb.

If ambient temperatures drop to near- or below-freezing, driving or rolling a vehicle equipped with summer performance tires risks the possibility of tread compound cracking. Tread compound cracking is a permanent condition that requires the tires to be replaced. The other condition that can be caused by running summer performance tires in cold temperatures is the possibility of chipping away the edges of the tread blocks.

Since both of these conditions only occur as the result of what's considered improper use or storage, they are not typically covered by the manufacturer's warranty.

Which vehicle parts go to the salvage yard 85% of the time without ever being used? If you haven't guessed by now, it's the spare tire, wheel, jack and tools. That's right, 85% of the time they will reach the end of the vehicle's life without ever having been used.

However, since the spare potentially represents one out of every five tires and wheels being manufactured for a given vehicle, it means up to 20% of the raw material and labor costs are being invested in a system that seldom gets used. And with the growing popularity of roadside assistance programs and cell phones, it's likely spare tires, wheels, jacks and tools will be used even less often in the future.

Spare tires are a cost to individual drivers and society in several ways:
First, the raw materials and labor costs associated with manufacturing spare tires, wheels, jacks and tools are included in the cost of the vehicle.

Second, they compete for room in the vehicle. They use space that could otherwise be devoted to a larger passenger cabin or more cargo capacity. Without a spare, designers have more flexibility in utilizing the vehicle's available space.

And finally, the weight of the spare tire, wheel, jack and tools reduce fuel economy throughout the vehicle's life. Sure, it may not be detectable on any one tank of fuel, but a 50-pound spare tire, wheel, jack and tools can reduce the vehicle's fuel economy by up to 1%. That means a 16 mpg SUV/light truck driven 150,000 miles during a 10-year lifetime would consume about 94 gallons of fuel just to carry the spare ($235 in fuel costs at $2.50/gallon). And even a more economical car that averages 35 mpg would still require 43 gallons of fuel during its 10-year, 150,000-mile lifetime ($107.50 in fuel costs at $2.50/gallon).


Does the trunk floor hide a spare tire, wheel, jack and tools or has the space underneath been devoted to the placement of other components?

In an effort to increase trunk size and component efficiency while reducing weight and cost, many vehicle manufacturers have deleted a standard spare tire, wheel, jack and tools. Sometimes drivers who don't feel comfortable without the security of a spare can include one as an option when placing an order for a new car; however most of the time their only option will be to carry a small compressor that can inject emergency tire sealant in case of a flat.

Placard Showing the Vehicle Never had a Spare

Buying a new car (or new-to-you used vehicle)? While you can look in a car's trunk or under a truck's bed, it may be easier to simply look at the tire placard on the driver's door jamb. Today's tire placards are vehicle-specific, listing the vehicle identification number (VIN) and confirming the Original Equipment (O.E.) tire sizes it was equipped with when it left the assembly plant. If the placard lists NONE (as shown above), it never had a spare and may not even have room to store one.

Look before you buy; it may keep you from being surprised the first time you discover there isn't a spare tire, wheel, jack and tools.

Adam wrote:SPID pics or it didn't happen.