2011 Ford Mustang GT 5.0: Our Production Example Less Powerful



By Jason Kavanagh | April 4, 2011

Last year, we dyno-tested a 2011 Ford Mustang GT powered by the company's hotly-anticipated 5.0-liter V8. That car was fresh from Ford's media introduction. It was strong. On the dyno and at the test track, it shone, and we were surprised by said strength.

We included some foreshadowing in that test: "Clearly, the 395 rwhp figure we measured is of particular interest since it implies one of two things -- either Ford is being conservative with its 412-hp flywheel rating, or the preproduction example we tested is unusually healthy. We're leaning toward the former, but we won't know for sure until we test a production 2011 Mustang."

Now, here, today, is our longterm 2011 Ford Mustang GT, the production one we purchased from a dealer just like everyone else. As promised, we busted out the dyno straps at MD Automotive in Westminster, CA, and got busy.

Let's jump right to the meaty bit. Here's what our longterm car did when strapped to the rollers of the Dynojet 248 chassis dyno:



Here's an overlay of those same results and those of the car from last year's media intro:



What the what? The car from Ford's media fleet is clearly stronger, generating some 12 lb-ft higher torque and 15 more horsepower at their respective peaks. At a given rpm, the maximum differences observed are even greater -- 23 lb-ft and 25 horsepower. These are not insignificant differences.

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.

We checked with Ford officials on the dyno results we observed, and they didn't come up with any smoking guns. That leaves plain ol' engine-to-engine variation, octane-sensitivity -- perhaps the car from the media intro still had Midwest premium in the tank (unlikely, according to Ford) -- or everyone's favorite conspiracy that the media intro cars were hotted up!

Same dyno, same operator, same equipment, same procedure. Weather conditions were very similar too, resulting in minimal weather correction in both cases. Green engine? At the time of testing, the car from the media intro had 1,750 miles on the clock to our 1,451.

In light of what you see here, which side of the fence are you on? Ford's a bunch of lyin' bastidges! or Easy now, there's perfectly reasonable technical explanation!

--Jason Kavanagh, Engineering Editor

http://www.youtube.com/watch?v=zY-v18TVAbo

 

I don't think this is a big deal, to be honest. The car has been proven to perform. It would be different if Ford were making outlandish claims and using a prepped vehicle like Nissan has with the GTR, but I don't think this is even remotely the same.

 

That's not a bad variance, I've certainly seen stock LS1 cars vary that much from car to car. Either way, stout car!

 

There's going to be a ringer out of the bunch every time. Why wouldn't Ford choose one for the media intro? I would.
The long term GT looks to have a flat spot at about 5400 rpm. Wasupwidat?

 

wht a bunch of morons (the magazine)... 380 rwhp is STILL more than 412 bhp..

 

harmonics?

 

^This^. Through secretly the Chevy loving side of me was hoping it was a ringer.

 

Yeah, and their longterm car still got very similar numbers to customer cars.

 

This was debunked on jalopnik. Other cars straight from dealer lots had similar numbers.

 

thats still good power.

 

Unless the car only has 9-10% drive train loss...

I have noticed that e.t's with the new 5.0's have been all over the board and pretty inconsistant from car to car...some are mid 12 second cars, some have their hand full breaking out of low 13's...

 

Some LS1 F-bodys run high 12s, some run low 14s, it's all in the driver. I don't think many have rand mid 12s, most I have seen are high 12/low 13.

I can't believe they are bitching about 15hp from one car to the next, that's only like a ~4% difference between the two.

 

While I certainly would not call that just a minor variance or no big deal, we have seen it before in other vehicles as well.
They didn't mention options or gearing differences (if any) between the cars, I'm assuming that they were both manuals of course but maybe one had 3.31 gears and the other had 3.73s?

 

Who gives a ****. The new 5.0 is still a sweet engine

 

True.

 

I almost wonder who paid the editor to run this story... It's not "just odd" to me, they'd go out of their way to point out such a small difference between 2 cars. If they had a slew of lower numbers vs 1 "prepped car," I could see the concern. They don't have that. Instead, we've seen several different, yet very similar sets of numbers.

 

Maybe they remembered the 1999 Slobra.

 

You mean the 99 that was overrated? They never had a problem with Ford giving out 99 ringers. 380whp with a 15% loss is almost 450 crank horsepower, so either way it's underrated. Maybe you should take a look at your own car, didn't the LS1 have about a 10% difference from the strongest motors to the weakest, with the same transmission/rear gears? Some trap ~105, some trap ~112 stock?

This is the reason this is a shitty article, because it is giving people a false reason to bitch about a car. 4% on two cars that were drove differently, dyno'd on different days, and with no mention of if they had the same gearing or not? And that's worth writing an article about? Please Either someone there doesn't like Ford at all, or they are getting a check from GM.

 

Where's the correlation? Is there a group of owners complaining that their cars are underperforming as sold? Is the current model underrated?

I don't see any connection here. I remember a few magazines running slower in the '99 than they had been expecting, then owners saying the same thing. Ford then recalled the cars for free fixes to bring them around to the expectations. I see no such example occurring here. If anything, most seem exuberant over their new 5L.

 

Ford had a slight better tune in the press car.....and who cares. Its a cut-throat market. They are pissed at the Camaro's rejoining the party, so they are hitting a little below the belt. Makes for good fun eh? I say carry on.