IMPORTANT NEWS: National Electric Vehicle Sweden has agreed to buy the assets of Saab Automobile and the sale is expected to be finalized during the summer.

Sunday, April 17, 2011

Saab corrosion protection

In countries where winter means snow, ice and temperatures below zero, and the road authorities use salt to keep the roads clean of snow and ice, one very important quality measure is the car's ability to withstand corrosion. The withstand corrosion the car manufacturers can e.g. use galvanization or zinc coating of the vehicle body and other vital components. Another measure is to use materials that don't rust, like aluminium, carbon fibre or plastic. To protect the chassis, it is common to use some sort of corrosion preventing agent, for instance tectyl or some sort of oil.

Here in Norway, Saab is known to produce car's that do a good job withstanding corrosion. The other Swede, Volvo, is also considered good, together with Germans like Audi and Porsche. Mercedes Benz has had some problems in recent years, as have Ford and Mazda.

But to get to the point of this blog entry, just how good is Saab cars construction and protected to withstand corrosion?
To answer that question I will turn to the Swedish magazine Vi Bilägare, which let's the anti-corrosion experts Rostskyddsmetoder AB look over the cars. These assessments are made on new cars based on the level of corrosion protection. To know just how much the car actually ends up corroding, we have to look at surveys of cars that have been used for several years. But today lets look at the expert assessments of the corrosion protection:

Saab 9-3 SportCombi, asessed 2009
Saab gets a plus that the bonnet and tailgate are made of aluminium. Both in the front and rear there are wheel arch liners that give good cover and some vulnerable joints are well sealed. Underneath the outer beams are extra protected with wax.

But our corrosion expert also discovers deficiencies. The rear doors have for example a forward pointing seam where the joint is completely unsealed and only protected by a (moisture collecting) rubber strip. Front doors also have an unprotected joint covered by a plastic strip.

- This car will rust in the doors like all other Saabs, states corrosion expert Thomas Widström.

The undercarriage is partially covered by an extremely thin layer of wear protection and large areas are completely unprotected. Some joints aren’t sealed. Saab has not spent money on mud flaps and the undercarriage will be blasted by gravel.

Score: Acceptable (3 out of 5 points)

Saab 9-5 Turbo4, assessed 2010
The new Saab 9-5 has a bonnet made out of aluminium and well ventilated wheel arches front. Even the rear wheel arches are nicely designed to resist corrosion and the arch liners front and rear have a sensible shape.

The sealing of the sheet metal joints on the doors and tailgate are also fully acceptable and in addition the doors (but not the tailgate) are treated with anticorrosive agent on the inside.

On the underside of the car however, only the most exposed areas are protection. Many joints, especially in the rear, are unprotected. On the negative side, it is also noted that the front strut housings are completely unprotected and in time it can turn into a rust trap.

On the positive side, protective coating has been used inside all beams under the car, but overall the rating is still only three out of five points for the new Saab car.

 - But the fourth point is within reach, says rust expert Thomas Widström. With some better wear protection, better protection of the strut housings and even more sealed seams on the undercarriage, the rating had been higher. 
Score: Acceptable (3 out of 5 points)

Saab 9-3X 1.9 TTiD, assessed 2011
The rear doors are missing sealing coating in the front and the wear protection underneath is neither fully covering nor sufficiently thick. The 9-3X specific plastic parts on the body can at best protect against impact and rock shots but risk collecting dirt when they over the years move in relation to the body.

The plastic parts can also prevent underlying corrosion from being detected. A good thing is the bonnet and tailgate which are made out of aluminium, and the beams under the car is properly sprayed with a anti-corrosion agent.
Score: Acceptable (3 out of 5 points)

My comment: When you own a Saab it's always a pre-emptive measure to be careful to wipe off the inside of the doors when you wash your car. And as with any other car, to consider to get extra protective coating on the undercarriage. Saabs get some protective coating when they are built, but when the car has been driven for a few years, it can be a good idea to get an expert to check if it needs a touch up.

Overall I would say that Saabs have good corrosion protection compared to most of the other car brands. But as we can read above, there are points that can be better.