Can air suspension survive a Canadian winter?

Automatic air suspension is wonderful — when it works. It keeps shorter-than-average drivers and passengers from complaining every time they have to make the steep ascent into Everest territory when they climb into the biggest of SUVs or pickup trucks. They can improve fuel economy by automatically lowering the ride height, and then can prevent body panel damage by jacking up over rough terrain. They can even convert what would normally be an uncomfortable ride into luxury-sedan smoothness.

So, with all this going for them, why would anyone not want them? Short answer: Our climate and roads.

Air suspension systems come in two basic variants: some use an onboard, selfcontained air supply, and others use fresh air. The majority of what’s available today fall into the first category, and when the system has its own air supply, the compressor does less work because it’s using pressurized air to start with. In addition, these systems are filled with processed nitrogen with most of its moisture removed. This is crucial because moisture is a main killer of air compressors.

For the short term, most air suspension systems can be fairly reliable. But since they’re usually included in higher-priced vehicles, they tend to see more distance and time on the road than entrylevel models — and that’s where things can get expensive. Compressors will fail for a number of reasons, and condensation or moisture are at the top of the list. Any dampness can cause internal valves and solenoids to jam and stick, blowing control fuses.

Our extreme temperature swings can bring more condensation than most compressors can handle. The result is usually a four-wheeled horse that can’t quite stand up straight; the vehicle will remain at low ride height, with its four airbags completely collapsed. For most vehicles, compressors start at about $2,500 before taxes and labour.

Among the other weak points are the individual airbags themselves. Even the best synthetic materials can dry and weather-crack over the years. When they lose their air-tightness, it’s time for a replacement — at about $1,000 a corner, to start, before taxes and labour.

On top of that, certain municipalities’ addiction to road salt means any time any work is done on an air suspension system, rusted air-line fittings will present trouble. While most technicians are good at splicing in new sections of brake or fuel lines, air-suspension lines are another matter altogether. They’re usually made of hard plastic and require complete replacement when a fitting or line section fails.

If you’re really set on a vehicle with air suspension, fork out the money for a good extended warranty that covers the compressor and air springs, at a minimum. In some cases, you can even replace air-suspension components with a conventional setup, either with OEM components from a lower trim level of your car, or with aftermarket parts. Either way, your wallet will thank you.