Do automakers provide juiced versions of their cars to journalists? It's a concern that goes back decades. Inside Line raised a red flag recently about the 2011 Ford Mustang GT. But is Ford really jucing?
Before we slap an asterisk next to the GT's horsepower figure, let's check this out. Edmunds Inside Line recently put its brand new 2011 Mustang GT long-term tester, a car the site purchased from a dealer, on a Dynojet 248 chassis dyno. The result indicated a peak horsepower figure of 380 and peak torque of 353 at the wheels.
What caused the red flag sendup? Inside Line had previously dynoed a press car from a 2010 media launch. Similarly appointed, that 2011 Mustang GT turned in peak figures of 395hp and 365 lb-ft.
Overlaying the two graphs, the differences in horsepower vary even more widely, reaching differences of 25 hp and 23 lb-ft. Off the dyno, performance tests revealed similar disparities:
The acceleration of the two cars mirrored the dyno results, too. Our black longtermer clicked off a quarter mile trap speed of 109.5 mph, fully 1.1 mph slower than the blue car from the media intro. More recently we tested a third 2011 Mustang GT 5.0 from Ford's media fleet which trapped 109.3 mph.
So, with the numbers working out in Ford's favor, is this just a case of typically variable horsepower figures found in most production cars, or is there corporate malfeasance afoot? Perhaps not the latter.
Back in 2010, during the same Mustang GT press launch, Motor Trend put a similar 2011 Mustang GT loaner on its own dyno. Its results were slightly different from Inside Line's press-loaner results. MT found a horsepower peak of 377.99 and torque of 351.44 lb-ft., or marginally the same as Inside Line's long-term tester.
Back in April 2010, Mustang 5.0 and Super Fords, which shares a parent company with Motor Trend, tagged along as tuning shop Evolution Performance picked up its new GT from the dealership and put it on the dyno. Evolution found the peaks were (in fifth gear) 368.60 hp and 352.48 lb-ft at the rear wheels, which was in line with both MT's press-car test and IL's long-term tester launch.
Naturally, there are plenty of variables in dyno testing, and so these results may not be considered empirically significant. But indeed, unless Ford is specifically trying to dick with Edmunds, it appears Ford's off the hook in the case, for anything but the sin of allowing an outlier to sneak into its media fleet. Conclusion: more testing needed.
So hop to it, buff books — and show us your dyno graphs!