M/T: EcoBoost Mustangs getting slower?

[kevm14]

Oh yeah, scandal time.

http://www.motortrend.com/news/ecoboost ... ng-slower/

Most recent and slowest:

Most recently, we tested a 2016 Mustang EcoBoost for a Motor Trend comparison test. It was tested on March 30, 2016. This car was equipped with the six-speed manual transmission and Performance package, and it weighed 3,622 pounds, the lightest we’ve tested. It was also the slowest, needing 6.3 seconds to hit 60 mph and running a 14.5-second quarter mile at 98.0 mph.

Oldest and fastest:

We tested our first EcoBoost Mustang on September 15, 2014. A 2015 model, it was equipped with a six-speed automatic transmission and the Performance package, and it weighed 3,658 pounds. That car hit 60 mph in 5.6 seconds and ran the quarter mile in 14.1 seconds at 97.8 mph.

Trap speed is nearly identical so if I didn't know any better, I'd say that was 100% launch related. But there's a lot more going on than that.

Ford said the faster one was preproduction so the later production ones could have had some calibration adjustments.

It seems like they are pulling timing/boost/throttle right after a hard shift. Maybe it is a trans/clutch/driveline thing (torque management). Or maybe it is for the engine itself.

[kevm14]

Interesting.

Excellent observation, and likely where the real culprit lies. As you can see, the cars accelerate nearly identically in 1st gear. It's 2nd and 3rd gear in which the slow car struggles, before the power comes back in 4th. Why is it doing this? We'd love to know. Clearly, the pulled power immediately following the 1-2 and 2-3 shift is the problem, as the curves appear equal in slope once the slow car stops pulling power.

But more interesting is this nugget. People complaining that C/D ran a faster trap speed. Remember the jokes about M/T's downhill drag strips and banked skidpads?

Despite every other reputable outlet switching to SAE J1349, CandD still uses the long-since-obsoleted J606 correction which is far more generous. You can draw your own conclusions for their reasons. In fact, go ask them.

So maybe C/D is the one with the inflated acceleration specs. And if I dig into it, I wouldn't be surprised if I learned that Edmunds was among the first, since they always had slower times than everyone else. Maybe now they don't.

[Bob]

Very interesting nugget. Since the trap is the same, I would say that the car isn't getting slower. For the people who still believe 0-60 is the ultimate measure of acceleration ability, I can see why they might believe it is slower now.

[kevm14]

This is a thing though.

this is something many car companies have been doing since at least the 90s. i'm surprised you guys are acting surprised, i thought it was common knowledge that as an engine / platform goes through its minor yearly iterations, it inevitably gets tiny tweaks that inevitably sap practical power/speed (usually in response to warranty data). nowadays the tweaks are mainly code stuff i'm sure -- dialing back the timing or whatever in certain situations that they discover (or suspect) are high-stress situations for problematic parts.

it was pretty obvious my 1995 Cadillac Eldorado Touring Coupe was significantly faster than my 1998 Cadillac Eldorado Touring Coupe, despite having supposedly the exact same engine. same deal with my 2006 300C SRT8 versus my 2010 Challenger SRT8 -- both the exact same 6.1 rated at 425hp, but the Challenger was demonstrably slower.

The same type of thing actually exists for the Northstar SRX. The first 04s were reported to be all kinds of snappy but also had pretty nasty driveline lash in certain low speed circumstances. They supposedly revised the calibration to numb that out, and there was also a reported CA emissions reflash that resulted in similar numbing of response and lower speed torque. What I never figured out is, how does my 08 fit in with all that? It seems to have pretty linear response and doesn't feel like it is powerless. But when I read the initial reviews of the 04, they sound like those cars ran like the early 90s Northstars and my 08 doesn't have that 90s snap or urgency to it. The 08 uses a newer generation of GM PCM than the 04-06 so possibly they were able to meet all requirements while maintaining full power/torque, but maybe with a little less snap. I mean, if you pound the throttle off a light, it launches pretty hard...