Alloy Wheel Specialists
The Wheel & Tyre Specialists - Powered by SCC Performance
info@rtecshop.co.uk 01727 790100
Search Login / Register 0 (£0.00)
  • Sale
  • Wheels
    • Search Wheels
    • Special Offer Alloy Wheels
    • Revo Alloy Wheels
    • Search tyres
    • Tyre code guide
    • Alloy Wheel Style Finder
  • Air Filters
  • Brakes
    • Brake Pads
    • Brake Discs
    • Big Brake Kits
    • Brake Caliper Paint
    • View All Brakes
  • Exterior
  • Engine
    • Diesel Tuning Boxes
    • Accelerator Response Booster
    • View All Engine
  • Exhausts
    • Search Exhausts
    • Exhaust Accessories
  • Suspension
    • Lowering Springs
    • Lowering Springs (adjustable)
    • Coilovers/Suspension Kits
    • Lift Kits (4x4, ATV)
    • Lowering Links (For O.E air suspension)
    • Air Suspension Kits
    • Anti Roll Bar Upgrades
    • Wheel Spacers
    • View All Suspension
  • Gallery
    • Vehicle Gallery
    • Instagram
  • Information
    • Price Match
    • FAQ
    • Testimonials
  • Technical
    • Alloy Wheel installation
    • Avoiding pot holes
    • Bedding in tyres
    • Correct tyre inflation
    • Performance benefits
    • Porsche N rated tyres
    • Mercedes MO rated tyres
    • Quality of a wheel
    • Reading your tyre markings
    • Selecting the right tyre
    • The age of your tyres
    • Tyre labelling
    • Tyre pressure monitors (TPMS)
    • Tyre rotation instructions
    • Tyre tread patterns
    • What are alloy wheels
    • Wheel alignment
    • Wheel nut/bolt torque
    • Why install larger wheels
    • Winter tyres
  • Blog
  • Services
  • Contact
  • Home
  • Blog
  • Tyre information

Tyre information

Wednesday 11th April 2018
  • From
  • Technical

How to check your tyre size

Use the guide below to easily and quickly find your tyre size from the side of your existing tyres.

A
Width

Look for a 3 digit number, such as 225

B
Profile

Which is followed by a 2 digit number, such as 55

C
Rim Size

And then a Rim Size, shown next to the letter R

D
Speed Rating

And finally the Speed Rating, identified by a letter (i.e V)

Tyre Labels

All tyres sold in the EU must be advertised and sold with the below format label, detailing Fuel Efficiency, Wet-Grip and Rolling noise (measured in Decibels).

Further information is available on the UK .Gov website (opens in a new window)

Load Indexes

62 265kg
64 280kg
66 300kg
68 315kg
70 335kg
72 355kg
74 375kg
76 400kg
78 425kg
80 450kg
82 475kg
84 500kg
86 530kg
88 560kg
90 600kg
92 630kg

94 670kg
96 710kg
98 750kg
100 800kg
102 850kg
104 900kg
106 950kg
108 1000kg
110 1060kg
112 1120kg
114 1180kg
116 1250kg
118 1320kg
120 1400kg
122 1500kg
124 1600kg
126 1700kg

Speed Ratings

You should check your handbook for the necessary speed rating before purchasing tyres. Using an inappropriately speed rated tyre could invalidate your insurance.

N - 87mph
P - 93mph
Q - 99mph
R - 106mph
S - 112mph
T - 118mph

U - 124mph
H - 130mph
V - 149mph
Z - 150mph+
W - 168mph
Y - 186mph

Factory tyre codes

MICHELIN
B – Tyres for Audi (S3, S4, TT, TT Roadster), Bentley – installed in pairs on the same axle, can be installed on other makes
C1 - Pilot Sport tyres for Chrysler Viper GTS Coupe - cannot be installed on different makes
G1 - A tyre with a larger external diameter; can be mixed with other tyres only when installed in pairs on the same axle (Mercedes: S, CLK, C, SLK, SL Classes - Rear axle, Alfa Romeo: 166, Fiat Stilo, Renault Laguna, Vel Satis), can be installed on other makes
K1 - Approved for Ferrari - cannot be installed on other makes
M0 - Approved for Mercedes - cannot be installed on other makes
N0…N3 - Approved for Porsche, cannot be installed on other makes
R1 - A special CXKA tread – a single tyre approved for Audi
* - Approved for BMW

CONTINENTAL
J - Original equipment in Jaguar
N0, N1, N2, N3 - Approved for Porsche
AO - Approved for Audi
RO1 - Approved for Audi models R and S
MO - Original equipment in special versions of Mercedes Benz (e.g.:AMG) and Maybach
* - Original equipment in BMW
M3 - Original equipment in M class BMW
E - Optimised rolling friction as required by original equipment

PIRELLI
(...) - Approved for factory installation
A - American version of Scorpion STR
M0 - Approved for Mercedes
N1...N3 - Approved for Porsche
(*) - Approved for BMW






Normal tyres with Run Flat wheels - Is it safe?

When it comes to BMWs (and some limited other manufacturers) the question is always the same - Can I use non-run-flat tyres with my O.E. wheels? Drivers seem to be uncertain, but the long and short of it: yes you can.

When it comes to the actual tyre sizes, they are 99 per cent identical and will sit correctly on your original wheels. The difference with the wheels, compared to those that would have come with non-run-flat tyres, is an extra hump behind the seating for the bead. The hump keeps the run-flat tyre in place while driving in 'run-flat' mode - i.e. without air pressure.

Therefore, this extra hump in your O.E. wheel is irrelevant when it comes to fitting non-run-flat tyres. The tyre simply sits on the outer, normal bead seal, performing exactly how a normal run flat would behave.

If the tyre is labelled numerically the same, for example, 225/40R18 RF and 225/40R18 non-run-flat - there will be no issue opting for a non-run flat tyre.

Obviously, in the event of a blowout, puncture, air leak or any other loss of air, you will not be able to drive on the normal tyre. The capabilities of run-flat tyres allow the driver to proceed at a maximum speed of XXX to the nearest garage to purchase a new tyre. Without this capability, you must pull over and make efforts to change the tyre to a spare, use a plug kit or an air compressor and tyre-weld product to seal any small punctures temporarily or call your roadside assistance.


Other time saving options include modern, specialy developed tyres with strong, puncture resistant seals inside such as the Pirelli Total Mobility Seal Inside concept found on Pirelli's website

Recent Posts

  • Rotiform Finally made a lightweight Track wheel

    Product News01.05.2025
  • COMING SOON: Risper Premium Low-Line Aero Kit for Volkswagen Transporter T7 (2025+) – Available at Rtecshop.co.uk

    Product News31.03.2025
  • New 2025 Transporter T7 Modifications Launched – Wheels, Styling & Suspension Upgrades

    Product Information27.03.2025
  • Predator Custom Body Kit for 2023> Transit Custom mk2 Vans

    Product News18.02.2025
  • New Additions to the Ford Transit Custom Mk2 product line up

    Product News14.02.2025

Browse by Category

  • Build threads
  • COVID
  • Events
  • General
  • Motorsport
  • Packages
  • Product Information
  • Product News
  • Special offers
  • Technical
  • Videos

Browse by Date

  • May 2025
  • March 2025
  • February 2025
  • December 2024
  • November 2024
  • February 2024
  • January 2024
  • December 2023
  • November 2023
  • October 2023
  • September 2023
  • August 2023
  • July 2023
  • June 2023
  • March 2023
  • December 2022
  • November 2022
  • October 2022
  • September 2022
  • August 2022
  • July 2022
  • June 2022
  • April 2022
  • December 2021
  • November 2021
  • October 2021
  • August 2021
  • July 2021
  • June 2021
  • April 2021
  • January 2021
  • December 2020
  • November 2020
  • October 2020
  • September 2020
  • August 2020
  • July 2020
  • June 2020
  • May 2020
  • April 2020
  • March 2020
  • February 2020
  • January 2020
  • November 2019
  • October 2019
  • July 2019
  • June 2019
  • April 2019
  • January 2019
  • October 2018
  • August 2018
  • July 2018
  • June 2018
  • May 2018
  • April 2018
  • March 2018
  • February 2018
  • January 2018
  • December 2017
  • November 2017
  • October 2017
  • September 2017
  • August 2017
  • July 2017
  • June 2017
  • May 2017
  • April 2017
  • January 2017
  • December 2016
  • November 2016
  • August 2016
  • July 2016
  • June 2016
  • May 2016
  • March 2016
  • February 2016
  • January 2016
  • November 2015
  • May 2015
  • April 2015
  • April 2014
  • April 2013
  • April 2012
  • April 2011
Key Products
Alloy Wheels Tyres Air Filters Exhausts Suspension Brakes Search All Parts
Information
Our Services Privacy & Cookies Terms & Conditions Returns Delivery Info Contact Us
Prices are subject to change daily.
Robert Oldman is a credit broker, not a lender and is authorised and regulated by the Financial Conduct Authority (FRN 755068) We do not charge you for credit broking services. Finance is introduced through the Omni Capital platform from a carefully selected panel of lenders. Omni Capital is authorised and regulated by the Financial Conduct Authority (FRN 720279). Omni Capital is a credit broker, not a lender and does not charge you for credit broking services. Whichever lender Omni Capital introduces you to, Omni Capital will typically receive a commission from them (either a fixed fee or a percentage of the amount you borrow). For your reassurance, all of the lenders Omni Capital works with could pay commission at different rates, but the commission received does not influence the interest rate you will pay. You will be offered the best rate available from Omni Capital's partner lenders, based on the lenders' decision policies.
Subscribe to our newsletter

Enter your email address to subscribe to our newsletter

A SCC Performance Company

Copyright of RTECSHOP.co.uk 2025 | All Rights Reserved
Developed & Hosted by DigtialFlare

A company owned by St Albans Car Clinic
Instagram - T&C - Privacy - Top
X

Offer