The material a tyre cushion is made from determines almost everything about how well it actually protects a vehicle's tyres — and it's the detail most likely to be glossed over in a product description. A cushion that looks similar to another can perform very differently depending on what it's made of and how it's engineered to behave under sustained load.
What a cushion material actually needs to do
A good tyre cushion has to satisfy two requirements that pull in slightly different directions. It needs to be firm enough to hold a contoured shape under the continuous weight of a parked vehicle — sometimes for months — without gradually compressing flat, which would defeat the purpose. But it also needs enough give to conform closely to the tyre's sidewall curve and maximise surface contact, rather than being so rigid that the tyre only touches it at a few points. Getting that balance right is a materials engineering problem, not just a manufacturing one.
Why EVA compound is suited to this
EVA — ethylene-vinyl acetate — is a closed-cell foam material known for a combination of properties that make it well suited to sustained-load applications: it resists permanent compression set better than many alternative foams, meaning it holds its shape rather than gradually flattening under continuous weight; it maintains consistent performance across a wide temperature range, which matters for a product that has to work in both a cool indoor garage and direct outdoor heat; and it's inherently weather- and moisture-resistant, without absorbing water the way some open-cell foams do.
ALTairEGO's cushions use a proprietary EVA compound specifically engineered around long-duration static load — the exact use case a tyre cushion faces, as opposed to foam designed for short-term impact absorption or cushioning in other applications.
How this translates to real performance
The practical result of getting the material right is that a cushion holds its contoured shape and its surface-contact benefit for the long term, rather than degrading after a few storage cycles. Combined with the sidewall cradle design used across the ALTairEGO range, this is what delivers the roughly 400% increase in tyre surface contact compared to a flat floor — a number that depends on the material actually maintaining its shape under the weight it's rated for, set after set, season after season.
Material quality is also what separates indoor/outdoor-rated cushions from indoor-only ones. A compound that degrades under UV exposure or absorbs moisture can't be reasonably rated for outdoor use, which is why ALTairEGO's full range — Super, Magna, and Leader — carries the same indoor and outdoor rating regardless of weight tier.
Why this matters when comparing products
When two tyre cushions look similar in shape and price, the material is very often where the real difference lies — and it's the difference that shows up not on day one, but after a full storage season, when a lower-grade foam has started to compress under load while a properly engineered EVA compound hasn't. It's a genuinely unglamorous detail, but it's the one that determines whether a cushion is still doing its job a year from now.
The takeaway
A tyre cushion's entire value proposition — reduced contact pressure, protection against flat-spotting, weather resistance — depends on the material holding its engineered shape under real, sustained vehicle weight. That's a materials science problem as much as a product design one, and it's why the compound matters as much as the shape.