Approved Tyres: Why Only Four SKUs Are Cleared

Four SKUs. That's It — and Here's the Engineering Reason

Quick Answer

Why only four tyre SKUs? INEOS validates each SKU through full electronic calibration — ABS, ESP, speedometer, traction control. Validating a single tyre SKU costs significantly, so only BFGoodrich KO2 (two sizes) and Bridgestone Dueler AT (two sizes) passed the programme. Running unapproved sizes introduces speedometer error (typically 5–9%), miscalibrated ESP intervention timing, and degraded ABS modulation. Staying within ±3% of factory diameter minimises the risk if you change.

The Approved List

Why Only Two Brands?

Each tyre must pass INEOS's validation programme which includes ABS braking calibration, ESP stability testing, NVH (noise, vibration, harshness) validation, and speedometer accuracy verification. The cost of validating a single tyre SKU through the full programme is significant, which is why only two suppliers made the initial cut.

What Happens When You Run Unapproved Tyres

ESP and Traction Control

The Grenadier's ESP system uses wheel speed sensors to detect loss of traction and yaw rate divergence. These sensors are calibrated to a specific tyre rolling circumference. Change the tyre diameter — even by 3% — and the ESP's calculations of vehicle speed, wheel slip percentage, and yaw rate all shift. The system may intervene too early, too late, or with incorrect force distribution.

"It has a great ESP, but it can't beat physics. The vehicle is very heavy — don't get me wrong, it works, but be aware that the ESP is calibrated for the factory tyre specification."

Speedometer Accuracy

The speedometer reads based on wheel rotational speed multiplied by the factory-programmed tyre circumference. A 265/70R17 BFG KO2 has an overall diameter of approximately 805 mm. Fitting a 315/70R17 (a common upsizing choice) increases the diameter to approximately 874 mm — an 8.6% increase. Your speedometer will read 100 km/h when you are actually doing 108.6 km/h. That is enough to trigger speed cameras, mis-calculate fuel economy readings, and cause odometer errors that affect service interval tracking.

"I like BFG AT2 but my Gren came with the Bridgestones — totally useless in snow or deep mud so I'm ditching them and going with a different tyre. My dealer was quoting £358+VAT for one BFG!"

ABS Performance

ABS modulation frequency and pressure profiles are tuned for a specific tyre contact patch, tread compound, and sidewall stiffness. Different tyres have different grip characteristics, and the ABS needs to know what "locked wheel" and "optimal slip" look like for the specific rubber on the vehicle. Running a tyre with significantly different grip characteristics can result in longer braking distances even with ABS active.

The Upsizing Temptation

The Grenadier community has an active contingent of owners fitting 33" and 35" tyres, often combined with suspension lifts. The engineering arguments for and against are well-documented:

Arguments For Upsizing

• Increased ground clearance (the only way to achieve it on a solid-axle vehicle)
• Larger contact patch for soft-terrain flotation
• More aggressive tread patterns for mud and rock
• Improved departure and approach angles (marginally)

Arguments Against

• ESP, ABS, and traction control miscalibration
• Speedometer error (typically 5–9% under-reading)
• Increased unsprung weight → worse ride, more stress on wheel bearings and CV joints
• Reduced steering lock in some cases (rubbing at full turn)
• Potential warranty implications on drivetrain components
• Higher centre of gravity (see our Grenadier centre of gravity and the 30% rule guide)

"I don't think I am going to lift my Grenadier until there are more reliable packages. I am hearing bad things and my mechanic is dealing with issues from aftermarket tyre and suspension changes."

The 3% Diameter Rule in Practice

The 3% diameter ceiling is widely cited in the Grenadier owner community — and it has a real-world backing. Many tyre retailers apply this as a hard limit for upsizes. The math is straightforward: a 265/70R17 has a rolling diameter of approximately 805 mm; a 295/70R17 sits at approximately 849 mm — a 5.4% increase, which exceeds that threshold.

"Costco has a policy that they cannot upgrade the size of a tire more than 3%. According to tiresize.com, 265 to 295 70r17 is a 5.4% change. They would not budge."

Tyre Pressure: The Variable Most Owners Ignore

Tyre pressure matters more than tyre brand for day-to-day driving. The Grenadier's TPMS (tyre pressure monitoring system) is set for the factory tyre specifications. INEOS publishes pressure recommendations based on load condition:

These pressures are validated for the approved tyre sidewall stiffness and load ratings. Running different tyres at the same pressures may result in different load-carrying capacity, different deflection characteristics, and different heat build-up profiles.

The Practical Approach

If You Stay Factory

The BFGoodrich KO2 is the better all-round choice for owners who venture off-road regularly. It has a more aggressive tread pattern, better sidewall puncture resistance (LT rating), and better mud/rock performance than the Bridgestone. The Bridgestone offers a quieter highway ride and marginally better fuel economy. Both tyres are what the DVA DualTrack Roof Rail system is tested against — our clearance measurements and load ratings are validated on factory-spec Grenadier vehicles running approved tyre and wheel combinations.

If You Want to Change

Stay within the factory diameter range (±3%) to minimise electronic system impact. Match the load index and speed rating to the original specification. Have the speedometer recalibrated by a dealer if you change by more than 2% in diameter. And accept that any ESP, ABS, or traction control warranty claim on unapproved tyres will be an uphill battle.

Build for the Grenadier It Actually Is

The approved tyre list defines the vehicle's performance envelope — not as a restriction, but as the foundation every system was engineered around. If you're building out your Grenadier for expedition or overlanding use, the accessories that work best are those developed with that same baseline in mind.

The DVA DualTrack Roof Rail is engineered and tested on factory-spec Grenadier vehicles with approved tyre and wheel combinations. The roof load distribution, crossbar mounting geometry, and accessory clearances are all validated against the stock suspension and tyre envelope. Adding a DVA Recovery Board Carrier or Side Accessory Carrier to a factory-spec Grenadier gives you genuine expedition capability without compromising the electronic calibration that makes the vehicle safe off-road.

If you're considering larger tyres and a suspension lift, build the accessories platform on the factory spec first — then plan the tyre/suspension upgrade as a separate, deliberate engineering decision, not an afterthought.

The Bottom Line

INEOS did not restrict the tyre list to four SKUs to limit owner choice — they did it because validating each tyre through the full electronic calibration process is expensive and time-consuming. The four approved options cover the two most common use cases: highway-biased touring (Bridgestone) and off-road-biased adventure (BFGoodrich). For most owners, one of these four will be the right tyre. For owners who want something different, go in with eyes open about what you are trading away.

Accessories Tested to Factory Spec

DVA Mechanics products are engineered and validated on factory-spec INEOS Grenadier vehicles with approved tyre and wheel combinations. Clearances, load ratings, and mounting geometry are all confirmed before anything ships.

DualTrack Roof Rails Recovery Board Carrier All Grenadier Gear