Used Vehicle Review: MazdaSpeed6, 2006-2007

2006 MazdaSpeed6; photo by Greg Wilson. Click image to enlarge

Test Drive: 2007 MazdaSpeed6 Test Drive: 2006 MazdaSpeed6 Manufacturer’s web site Mazda Canada

By Chris Chase

Fans of small, sporty cars may remember something called the Mazda 323 GTX: it was a turbocharged all-wheel drive version of the late 1980s-era 323 that still has something of a cult following.

It took another fifteen years for Mazda to once again combine a turbocharged four-cylinder engine with all-wheel drive in a performance car – this time in 2005, with the MazdaSpeed6. While the car was originally set to go on sale early in the summer of 2005, production delays meant it didn’t reach showrooms until near the end of that year.

Following a similar formula used by the 323 GTX, the MazdaSpeed6 was powered by a turbocharged four-cylinder engine, which put its power down through the company’s then-new Active Torque Split all-wheel drive system.

274 horsepower is a lot, and it’s even more so with 280 lb-ft of torque to back it up. Even in top gear (the only transmission was a six-speed manual) the motor had enough punch to provide useful acceleration at highway speeds, and acceleration in lower gears was downright scary for the unsuspecting driver (or their passengers!). Even better was the fact that when driven sedately – something that takes extreme restraint – the MazdaSpeed6 would return reasonable fuel consumption numbers. According to Natural Resources Canada, it was rated at 12.5 L/100 km in the city and 8.5 L/100 km on the highway – only a few tenths of a litre higher than the V6-powered Mazda6.

2006 MazdaSpeed6; photo by Greg Wilson. Click image to enlarge

Coming under the too-damn-bad heading is the fact that the MazdaSpeed6 could be had only as a sedan, where the non-Speed Mazda6 was available in hatchback and wagon body styles. Still, if all you needed was a useful back seat and four doors, the MazdaSpeed6 was a good fit. One downside, at first glance, is the lack of a folding rear seat, but it actually can be folded down – with the use of tools, thanks to a structural brace that lives behind the rear seatback.

There have been a few reliability problems, despite Mazda’s generally strong reputation in this area. One appears to be a rash of broken differential mounting brackets and drive axles, in many cases on cars with low mileage. As with many reasonably-affordable, high-powered cars, it’s tough to say if this is a build-quality issue, and/or if the drive-train isn’t quite capable of handling the engine’s power, or if it’s the result of abuse by “enthusiastic” drivers. Also, owners complain of a whining noise from the rear differential. My opinion is that if you’re gonna build a car with this much power, you gotta build it to withstand high-rev, clutch-drop launches and other shenanigans: many buyers of cars like these are going to drive the crap out of them.

There’s also an issue in 2006 models with overly-sensitive knock sensors that prevented the throttle from opening fully when the driver mashed the gas pedal. This could be related to another complaint from some owners that their cars seem to have been delivered filled with regular unleaded (87 octane) fuel, instead of the premium (91 or 93 octane) fuel that high-strung turbocharged engines prefer; the result is diminished performance (Mazda says 87 octane can be used in an emergency if nothing else is available).

Perhaps that hesitation is related to a “stutter” at wide-open throttle, a DIY fix for which can be found here.

Grinding gears when shifting could be caused by failed/failing hydraulic clutch master and/or slave cylinders, or bad engine/transmission mounts.

2006 MazdaSpeed6; photo by Greg Wilson. Click image to enlarge

Some owners have had issues with leaking turbo seals that allow oil to get into the intake air stream. A potential solution is to use a heavier-grade engine oil — say, 10W40 instead of 10W30.

A whining rear differential is a common trait too, but it’s not certain whether it’s normal or not. What’s certainly not normal is the fragility of the front and rear differential mounts. They will apparently hold up fine in normal driving (as that would be defined for most cars), but not for the kind of “normal” use that a 274-hp, AWD sport sedan is going to be subjected to, at least some of the time. Here’s a link to an upgraded aftermarket front diff mount, and this replacement rear differential brace is said to fix that pain in the rear.

This post at Mazda6Club.com suggests ways to avoid carbon build-up on the Speed6’s intake valves – a common problem in cars with direct fuel injection.

In the U.S., Mazda issued a technical service bulletin to address a problem with high clutch pedal engagement and poor feel, and a few owners on Mazda6Club.com complain of grinding from the transmission. There appear to be some general transmission reliability issues.

2006 MazdaSpeed6; photo by Chris Chase. Click image to enlarge

Mazda6Club.com has this MazdaSpeed6 new-owner summary thread that details the car’s common problems and links to discussions about most of them. One of those linked discussions is this how to find a turbo boost leak how-to. Also handy is this thread, which lists links to all kinds of other useful information.

The Mazda6 in general has fared well in crash testing, earning five stars all around in the National Highway Traffic Safety Administration’s front crash tests, and early models earned three and four stars for front and rear seat protection in side impacts, while 2006 and newer versions got four stars each.

Over at the Insurance Institute for Highway Safety, the Mazda6 got a “good” rating in that organization’s frontal offset crash test, but scored “poor” in side impact tests.

2007 MazdaSpeed6; photo by Jil McIntosh. Click image to enlarge

Comparing the MazdaSpeed6 to a pair of sedans with similar missions — Subaru’s turbocharged Legacy GT and the Volvo S60R — the Mazda is the least expensive by a wide margin. Along with that discount, you take a hit in refinement, and Subaru’s all-wheel drive system is superior in its operation, too. And then, the Subaru could be had as a station wagon, even in this performance-oriented versions.

I like the MazdaSpeed6 quite a lot, but its fragile drivetrain suggests the car was underbuilt for its performance potential. The MazdaSpeed6’s short production run may make it something of a bargain-priced collectible, but I’m not sure that alone would be enough to buy one over a similar car that’s simply more dependable when driven in the manner it was designed to be.