Mazda MX-5: A Successful Diet Programme | Part Two

The soft top is still manual like before - so Mazda could avoid the heavier solution here of an electro-hydraulic retractable top.

By weight, 58 per cent of all body components of the new Mazda MX-5 are made of ultra high-strength steel or high-strength steel, which save 10 kg. Using aluminium for the bonnet, boot lid, the powerplant frame, front suspension control arms, rear hub carriers, rear brake callipers and rear suspension spring seats reduces weight even further. The front suspension control arms and the hollow front stabilizer alone cut 6.2 kg of unnecessary weight at the front axle.

Revolutionary Welding Process for the Boot Lid

Spot friction welding, a process first employed on the Mazda RX-8, is used for the boot lid of the new Mazda MX-5. This process, for which Mazda has registered 20 patents, joins zinc covered steel and aluminium panelling. Employing a high-speed spinning tool creates enough heat to spot bind these very different materials to one another. The employment of zinc-coated steel sheeting has other advantages as well. Since zinc melts and runs when heated, it removes the oxidation surface that would otherwise remain at the spot the two metals are welded together, and only without this is a truly robust spot weld possible, because it prevents the chance of corrosion. This process also saves large amounts of electric current needed for traditional spot welding, and the boot lid is now 2.5 kg lighter as well.

Other examples of lightweight construction are the intake manifold (- 2.4 kg) and the cylinder head cover (- 1.3 kg), both being made of plastic. Mazda’s gram strategy also dictated mounting the power steering pump and the air conditioning compressor directly to the engine, which did away with the need of a bracket and saved 3.2 kg. The engines themselves are also lighter than the engines of the outgoing model. The block of the 2.0-litre, for instance, is 5.4 kg lighter than the grey cast-iron block of the 1.8-litre power unit of the previous model.

continues... | Part Three
Published 14 October 2005 Melanie Carter

The information contained this Mazda MX-5 news article may have changed since publication on the 14 October 2005. Our car specifications, reviews, and prices may only apply to the UK market. You may wish to check with the manufacturer or your local Mazda dealer, before making a purchasing decision. E.&.O.E. You may NOT reproduce our car news in full or part, in any format without our written permission. © 2018