OE branding

What are OE tyres? OE tyres are Original Equipment on certain makes and models of cars, but they are not simply a throw away specification.

Most boil down to these two groups, R&D which are built and designed alongside the development of the car to maximise the tyres potential performance, complement/maximise the vehicles handling dynamics and improve driving characteristics and to improve road and driver safety. Methods used are modifying the tyre with compound adjustments, changes to the shoulder and/or tread profile design, even sidewall rigidity are adjustments amongst others. The second is what we call, a ‘blueprint’ or donor tyre used in the development of the vehicle, these are generally tyres already in circulation and have been chosen by the manufacturer during the R&D phase to design the car around, these usually do not get the coveted ‘printed’ car manufacturer OE branding. Like the Lotus Evora and Lotus using MO (Mercedes) fitment tyres during development and retail release.

Due to the unique specifications of these tyres and the association with high performance manufacturing, Bridgestone, Continental, Dunlop, Falken, Goodyear, Kumho, Michelin, Pirelli and Yokohama are the most commonly used manufactures of these very high performance tyres.

The easiest way of identifying if your tyre is OE is by way of the sidewall markings printed on the tyre. These unique markings indicate that a tyre is approved by the vehicles manufacturer, in the trade known as ‘Homologated’. The tyre manufactures can not indicate approval on their own, even if in theory or practice they are suitable.


Need help finding an OE tyre for you vehicle, contact us at Turner Tyres and we will be happy to help find what you need.

load ratings

Load ratings are important when you need to match a tyre to a specific purpose or car, track cars, commercial use or private. Most sizes come in:
  • Standard Load
  • Extra Load / Reinforced (abbreviated XL or RF not to be confused the RunFlat).
  • Commercial (abbreviated C) which usually has a dual load rating based on pressure (107/105) and/or an associated PLY
----------------------------------------
Load rating is the MAX weight a single tyre can take at its MAX pressure.
So for example, a 91 rated tyre would have printed on its sidewall,
"Max Load of 615kg at Maximum pressure of 44 PSI or 3bar".
MAX LOAD = When you divide the cars total weight by the number of wheels!
But you would not want to have 44psi in the tyre usually, you would usually be running lower than that, to aid in ride comfort, even out tyre wear and increase road surface contact.
Which is why the total of the "Load rating x amount of tyres" is usually a lot higher than the actual curb weight of the vehicle, to allow for lower inflation without compromising the load holding, and improving other characteristics.
This also creates a nice buffer between your vehicles curb weight and the max tyre load to allow for additional passengers and baggage without exceeding the tyres load rating.

A few things to consider:
  • Load Rating is per tyre, not total weight of vehicle, so using 91 as our load, that's 615kg x 4 if you have a 4 wheel vehicle to give you the MAX LOAD your tyres can take.
  • The majority of road users do not have the need to change tyre size, so stick to what you have unless you are overloading your vehicle.
  •  Most sizes come in only two rating options, stick to stock, but if you go higher or lower, pressure may need to be adjusted.
  • The load rating should not be exceeded when passengers and luggage are accounted for, which is why the rating is usually higher than the actual vehicle weight to allow for this and reduced MAX inflation without compromising the structure of the tyre.
  • There is a formula that can give you a close 'perfect pressure to Load rating'. Its not exact, as it does not account for the weight difference over axels based on engine position and a few other factors. But its a good starting point for some trial and error testing.
  • Changing tyre size can impact rolling radius, which can impact speedo reading, TPMS, TCS and ABS sensors, so take that into consideration.
----------------------------------------
You may ask, "Why does my car has such large tyres?"
Its not just for looks, the structure of the tyre to reach the load rating can impact cornering feel, handling, ride comfort, road noise amongst other things.
Tyres are absolute, they have a size, load and speed rating and its an industry and world wide standard. The manufacture of a car cant just pick any tyre size and ask the tyre builder to modify and tailor the load and speed ratings for every model the car manufactures make that have that size, its cost too much and wastes too much time (Its not like the reasons for OE TYRES see above).
So what they tend to do, is they find out the curb weight of the vehicle and pick a selection of tyre sizes that exceed the load rating needed, make pressure adjustments, do some testing and go from there.
----------------------------------------
General rule of thumb...........stick to what the manufacturer recommends on the door card or in the vehicle user manual, if you notice uneven wear, adjust pressure accordingly. The load guide shown is a general guide to explain what load ratings you would need for a specific weight, its not a fault free guide, but it gives a general idea.

With wheel sizes being changed via aftermarket wheel applications, modifying vehicle use, OE load rating might not be possible, contact us and we can help you find the tyre you need.

And when making changes to Load rating beyond a single code (due to a tyre size change), notify your insurance company, as trivial as it sounds and usually not costing anything when you notify them of the change, some insurance companies do class a significantly lower rating as a modification as its no longer inside the manufacture specification, similar to changing tyre size or swapping run-flats for non run-flats.

Speed rating

Not quite as in depth as our Load rating explanation.
As with load ratings, speed ratings are just as important. This rating indicates the speed a tyre can achieve for an extended period of time before it begins to show signs of failure or performance/grip drop off. Most vehicle wont reach the high speeds indicated, but its not just about top speed, it also helps indicate its resistance to deformation due to acceleration torque and cornering speed, even braking weight transfer also plays a factor in choosing a speed rating.

And when making changes to speed rating beyond a single code, notify your insurance company, as trivial as it sounds and usually not costing anything when you notify them of the change, some insurance companies do class a significantly lower speed rating as a modification as its no longer inside the manufacture specification, similar to changing tyre size or swapping run-flats for non run-flats.


© All rights reserved Website in active development (PUBLICver6.0.0)
Website owned and maintained by Turner Tyres.We take no responsibility for information listed on this site if it comes from outside sources. For details on the information from outside sources, contact info.turnertyres@gmail.com.