Weight rating is the single most important spec on a tyre cushion, and it's the one most likely to be overlooked in favour of price or appearance. A cushion under-rated for a vehicle's weight won't hold its shape correctly under sustained load, which undermines the entire point of using one. Here's how to think about it by vehicle category.
Why weight rating exists in the first place
A tyre cushion works by spreading a vehicle's weight across a larger contact surface than a flat floor would. But the cushion material itself — in ALTairEGO's case, a proprietary EVA compound — has to hold its contoured shape under that load without gradually compressing flat itself. A cushion rated for 2,000kg tested against a 3,500kg classic sedan will, over time, start to compress under a load it wasn't engineered for, which erodes the surface-contact benefit it's supposed to provide. Matching rating to actual kerb weight isn't a formality — it's what makes the product work as intended.
Sports and performance cars — up to 2,000kg
This bracket covers most of what people picture when they think "sports car": Porsche 911, Ferrari's lighter-bodied models, Lamborghini, BMW's M cars, and the Nissan GT-R. These vehicles combine relatively low kerb weight with high-performance tyres, and ALTairEGO Super is built specifically for this range — standard cushion thickness, full sidewall cradling, and the same 400mm max tyre width and EVA construction shared across the whole range.
Heavier performance and grand tourers — up to 2,750kg
Cars like the Mercedes-AMG GT, Bentley, Aston Martin, and Maserati carry meaningfully more mass than a typical sports car while still being performance-oriented. ALTairEGO Magna uses increased cushion thickness specifically to hold its shape under this heavier bracket without compromising the surface-contact benefit.
Classics, luxury, and SUVs — up to 4,000kg
Rolls-Royce and similarly heavy luxury vehicles, classic and vintage cars, and SUVs sit at the top of the weight range and often carry the added risk factor of older or less UV-resistant tyre compounds in the case of classics. ALTairEGO Leader is built with maximum cushion thickness to match — the highest-rated set in the range, designed for exactly this category.
What happens if you undersize
Using a cushion rated below your vehicle's actual weight doesn't cause sudden failure, but it does mean the cushion compresses more than it's designed to and provides less of the surface-contact benefit over time — you lose some of what you bought the cushion to achieve in the first place. If your car sits near the top of a bracket, sizing up to the next tier costs relatively little compared to the vehicle and tyres it's protecting, and removes any question about long-term performance.
A quick way to check
Look up your vehicle's kerb weight — not gross weight, not with passengers, just the manufacturer-listed curb weight — and match it directly against the three brackets above: up to 2,000kg for Super, up to 2,750kg for Magna, and up to 4,000kg for Leader. All three share the same 400mm max tyre width, full sidewall protection, and indoor/outdoor rating — weight capacity is the variable that separates them.