If the 2015 Mustang is heavier than its predecessor, would it really be a surprise?
By Steve Turner
Photos courtesy of Ford Motor Company
If the Internet had a favorite car, youâ€™d have to think the Mustang is one of the leading candidates for that title. This is especially true during the news-cycle courtship that takes place leading up to the release of an all-new Mustang. With a public hungry for new intelligence, the vacuum left between official news releases creates a viral breeding ground.
Last week rumors that the 2015 Mustang would be heavier than its predecessor exploded to temporarily fill that void. Now, it doesnâ€™t take much to get people excited about a new Mustang, which is great. However, I have to say that I was taken aback by the seeming shock over the slightest possibility that the car would be heavier.
Really? This would be a surprise?
I was always perplexed by the rumors that the car would be lighter. Iâ€™m not really sure how that started. Maybe someone heard something about a pre-production car? Who knows? However, I never really believed that the Mustang could gain an independent rear suspension and somehow end up lighter. Sure, it is possible if Ford turned to lighter, more expensive materials. However, there are costs to consider as wellâ€”though Ford’s lightweight Fusion concept portendsÂ a corporate diet…
All this started because of a post assuming an IRS Mustang would be heavier. This is not a wild stretch of the imagination. In fact, we need only look back to the last IRS Mustangâ€”the 2003-2004 Mustang Cobra. Way back then, the 2004 Mustang GT weighed in at only 3,317 pounds. It was a flyweight compared to the outgoing 2014 Mustang GT, which tips the scales at 3,618 pounds.
No one is complaining that the heavier 2014 gives up any performance to the 2004. Granted the powertrains are vastly different, but the fact remains the heavier car is a superior performer. However, both the 2004 and the 2014 are eclipsed by the weight of the 2003-2004 Cobra. It crossed the scales at 3,665 pounds. Sure, some of that mass was courtesy of the iron block, supercharger, and support hardware. However, at least 80 pounds of it was from the independent rear suspension. For example, the naturally aspirated 2001 Cobra was still 193 pounds heavier, at 3,430 pounds, than its 3,237-pound GT sibling with the solid axle.
Thatâ€™s exactly why I was never there with the rest of the media complaining that the Mustang rear suspension was â€œantiquatedâ€ every time a new car was released. Even as the Boss 302 took solid-axle handling to new heights, the question still came up at every media launch. Now, Iâ€™m not saying that an IRS doesnâ€™t work. A properly executed independent rear suspension works well, especially on uneven surfaces. Those bumpy roads are theÂ Achilles’ heel of the solid axle.
Of course, I say properly executed, because even Ford engineers admit the Cobraâ€™s IRS was a compromised design. In my experience, its combination of spring and damper tuning was so taut that it mitigated the benefits of the IRS on rough surfaces. The same could be said of my limited experiences in the early versions of the modern Camaros, though they have obviously come a long way.
So an IRS can obviously improve the handling of the Mustang, but at what cost? Well, weight, expense, and drag strip limitations are the potential down sides. It certainly remains to be seen how these potential opportunity costs will play out on the S550. However, it will be interesting to see the mainstream auto media transition its long-running rear suspension complaint to one of excess weight, because the weight can likely be attributed directly to the suspension they demanded for so many years.
Yes, you can have an independent rear suspension, but donâ€™t expect it to come without sacrificing something.
Now, lest you think I am joining the chorus of those complaining about weight, Iâ€™m not. Yes, I would love it if the new Mustang were lighter. I just never bought into that. In the end, if the Performance Pack-equipped Mustang GT handily outruns the vaunted Boss 302, the noise about weight will quiet. Dropping weight will improve performance, but if the performance is impressive the weight is less of an issue. You need look no further than the comparatively portly GT500 to see that.
So what is more important to youâ€”a lighter Mustang or an independent rear suspension? Donâ€™t say both, â€™cause thatâ€™s just cheating reality.