Unsurprisingly, your car’s tyres are one if the most important parts of your car, so it’s important to know about them. This video should help, as I cover size, load and speed ratings, style, compound, tread and pressures!
- Tyres are really important
- It’s the only thing that connects your 2 tonne pendulum to the road
- Contact patch – it’s small but oh-so-grippy
- Size
- Markings on the side of the tyre – 255/35 ZR19 96(Y)
- 255 – Tyre Width in mm
- 35 – Aspect ratio (height) as a percentage of the width (35% of 255, 89.25mm)
- ZR – Radial (ZR used to mean high performance, now not functional)
- 96 – load rating – 710KG
- (Y) – Speed rating – 186mph+
- Extra tyre markings like treadwear, traction and temperature are manufacturer provided/suggested markings, not necessarily accurate or standard.
- Style
- All Season – most vehicles should probably be on these, work well across the standard temperature range for conventional driving. Grips in the cold, should still mostly stick in the warm. Not great for performance driving
- Summer – work great in warmer weather, often lacking wet and cold performance.
- Winter – great cold/wet performance, naff in summer
- Energy Saver – less rolling resistance, but also generally less grip
- UHP – ultra-high performance, what I have, works best when warmed up, really naff in the cold and snow
- Low profile – often comes with UHP, smaller sidewall for less flex and better handling, but worse ride quality
- Run flat – Mini has these. This doesn’t mean bulletproof, this means reinforced sidewall. Can drive 50 miles at 50 miles per hour on the flat before the sidewall gives in. Gets you home/to a garage, not to be driven on, generally “can’t” be repaired
- Offroad / mud / snow / ice – more specialised, very different designs, often larger profile (sidewall) and can even have spikes for ice.
- Compound
- Varies depending on style, mostly on what temperature the rubber is activated at
- E.g. Winter tyres generally work at 7°c or lower, supper is 8°c and up. UHP often needs to be properly warmed up before giving full grip.
- It’s also a graph, not just a range. eg:
- Tread pattern
- Makes a big difference depending on conditions and use
- Winter tyres will have more & larger grooves
- Summer tyres will have as few as they can
- Mud tyres have knobs that can act like paddles
- Pressures
- Pressures are set per vehicle and based on load, conditions and speed – done a full video on that but TDLW check your door jam or owners manual and pick the pressure that corresponds to your needs, i.e. load and speed, and potentially vary them by +-3PSI based on temp and conditions, ie colder = lower, warmer = higher.
- Tread depth
- 1.6mm across the centre ¾ of the tyre – wear indicators included
- Low tread depth means water can’t evacuate, can cause/exacerbate hydroplaning
- Age code
- DOT code – week + year, eg 4220 – 42nd week of 2020.
