Project E90 M3: Head to Head with 2016 Mustang GT

Next up was the Mustang GT. Sitting behind the wheel of the Mustang, the seats don’t have the same level of side support as the M3, but the California Special’s grippy Alcantara seat inserts do a lot to help to keep you in place.  While the leather quality of the seat and steering wheel is decent by American standards, they are not at the same level of the M3’s high-end Napa leather.  However, it is quite comparable to the leather in a standard 3 series.  The steering wheel is a standard diameter and is not as thick as the M3’s wheel.  Personally, I like the fat feel of a thicker wheel.  Outward visibility is good but the long, flat hood does make the car feel large.  This is greatly improved on the GT350 and 2018 Mustangs with their lower, raked hood line.  The driving position is quite good with a fully adjustable steering wheel, but like most cars short of Porsches, I would prefer the seat having adjustment to go lower.


I set the driving mode to Sport, then held the Traction Control button for 7 seconds to turn off the “AdvanceTrac” stability control.  Pulling out of pit lane, there’s no denying that this is a torquey American V8.  The 5.0L Coyote V8 makes 86% of its peak torque at 2,500rpm and has a constant thrust all the way to its 7,000rpm redline.  The throaty engine sound is mostly induction noise piped into the driver compartment and overall the Mustang is way too quiet in stock form for a Muscle Car, Pony Car, Sports Car, whatever label you want to give it.  But thankfully due to the best aftermarket support in the industry, that problem is easily fixed.


Rowing though the gears of the Getrag MT-82 isn’t as bad as most people make it out to be.  While it’s not the best transmission in the world, it’s far from the worst.  Most of the MT-82’s bad reputation comes from S197 equipped cars, and many S550 owners simply regurgitate what they read on the internet of the S197 MT-82 problems.  In reality, by the time the S550 came out, Ford made a lot of small changes to the MT-82 including hardware, clutch springs, gear finishes and oil specs.  The S550’s MT-82 also has a different shifter bushing and bracket for firmer, more precise shifts.  The Mustang GT’s used in the Ford Performance Racing School in Utah receive a lot of abuse, and they are holding up quite well.  Overall the MT-82 requires little shifting effort and with a short throw, shifts happen quickly and effectively.

The drivetrain of the Mustang is noticeably more ‘squishy’ than the M3’s.  The Mustang’s differential and subframe have large rubber bushings with large voids which allow for a lot of movement and wheel hop when launching the car and drag racing.  Fortunately we are not drag racers so this isn’t as big of an issue for us.  All of this rubber usually results in a vague and sloppy handling, but with a 28% torsionally stiffer chassis and ground-up new suspension design, the rubber bushings do not diminish the handling or response like a Foxbody Mustang or Cadillac.


Turning into a corner, the Mustang’s Electronically Power-assisted Steering (EPS) suffers from the same lack of feedback and ‘video-game’ like isolation when compared to a traditional hydraulic rack, but most manufacturers and even EPS equipped racecars run into this problem.  I prefer the heavier steering of the “sport” steering mode which is heavier across the board and does nothing to add feel.  Normal is lighter and I’m not sure how some people like tracking the car in “Comfort” which is excessively light and too responsive to inputs, but some people prefer it.  I must say I don’t see many advanced drivers tracking their cars in comfort mode.

On corner entry, front grip is the limiting factor but understeer is not terminal or excessive.  The car takes a distinctive set after turn-in then remains planted.  The body control is not as tight as the M3s but the car remains stable and the body movement is easily manageable.  More low speed damping would be preferable to improve transient response as would a stiffer rear swaybar.  Mid-corner, a mild understeer is the limiting factor and the car is not as responsive or ‘twitchy’ to steering inputs as the M3 which makes it far more stable and easier to drive with plenty of rear grip to spare. While it sounds contradicting, despite the increased body movement, the car feels like it has a lower center of gravity.


Braking force was good but like the M3, the stock OEM pads were the limiting factor and started to fade after a few hard laps at the limit.  Having tracked many 2016 Mustangs with the larger 6-piston, 15-inch “Performance Package Brakes, they hold up far better with stock pads and after upgrading to a mildly more aggressive pad, there’s no need to ever ‘upgrade’ to a Big Brake Kit, although lighter weight 2-piece rotors would be a benefit.


Where the Mustang shines is putting power down.  Combined grip is excellent and you can get on the throttle aggressively and it hooks up.  One major reason behind the Mustang’s grip is due to the rear suspension geometry and roll centers.  As the Mustang squats and rolls, the rear roll center drops, which increases rear grip.  Adding the Performance Package’s larger 275 rear wheels and tires likely exaggerated this rear grip since the PP also comes with a stiffer rear swaybar and different dampers, exactly what this car needed.

Across the finish line the Mustang clocked an impressive 1:32.952, which was 0.873 seconds faster than our M3.

MotoIQ Motec Data Project E90 M3 vs 2016 Mustang GT PBIR
This data overlay is impressive.  Despite all of the differences in the cars weight, gear ratios, power, torque, and from two completely different manufacturers, you could look at this graph and say they were from the same car with a fairly consistent driver. It’s not until you look at the RPM or the full throttle upshifts on the straight that you realize they are actually two different cars.

When comparing the Mustang’s 1:32.952 lap (red) to the M3’s 1:33.825 (black), the first thing that sticks out is the RPM difference.  While both cars are almost always in the same gear, the M3 is typically 1,500rpm higher in the revs than the Mustang thanks to its shorter gearing and higher redline, which is crucial for making the same power out of a smaller engine.  The next and most impressive thing is how closely these vastly different cars overlay to each other.  On the straights you can see the Mustang just slightly out-accelerates the M3 but that gain is lost due to the time it takes to shift the manual transmission.


Looking at the data was eye opening.  Despite a moderate difference in subjective feel, our Project E90 M3 and this 2016 Mustang GT CS were virtually identical on track.  While both cars used the same Continental Extreme Contact DW tire, the Mustang has a 10mm wider tire front and rear, but carries an additional 100lbs.  The only way for these cars to be that similar is to have similar power (which they do) and a similarly competent chassis.  Keep in mind this the M3 is the top of the line 3-series while this Mustang GT was as ‘base’ as you can get.  The Performance Package is quite a step up and the GT350/R is on a different planet.

MotoIQ Motec Data Project E90 M3 vs Mustang GT cornering data PBIR
Entering Turn 3, the Mustang (red) has greater combined loading and ability to trail brake with higher entry speed than the M3 (black).  In the middle of the corner, the cars were pretty evenly matched pulling 0.92 to 0.93 Gs on the Continental DW tire which is pretty impressive for the abrasive track surface.  Exiting the corner, the Mustang continued to show its greater combined grip and power-down abilities by getting to the power sooner and being able to put it down with a better exit.
MotoIQ Motec Data Project E90 M3 Mustang GT braking PBIR
Braking at the end of the straight from 135mph was pretty even as well.  The Mustang (red) spiked a slightly higher peak deceleration force of -0.96 Gs while the M3 (black) was a little more even and produced -0.88 Gs.  The overall deceleration rate of both cars were very similar and both cars started to fade the brakes after a couple laps, signifying that the factory brake pads and fluid are not up to extended track abuse.

I’m a fan of what BMW does with their suspension on the M3 to give the car a great ride and handle well on track, characteristics that are lost a bit in the new F8X M3/M4.  The M3 is very playful and on its toes, but the skating nature of the chassis makes it feel like it has high roll centers and rides on the bumpstops to limit roll at the cost of grip.  Meanwhile the Mustang has a great ride, but it’s compliance makes it a little soft on track, a little less dramatic, but that compliance does help it generate grip and overcome its weight.

Both cars need to give up a little of their strength for overall balance.  The M3 needs wider tires for them to bite and handle the load better and a much-needed improved power down ability, while the Mustang needs a bit stiffer suspension to be slightly more responsive to inputs.  Having said that, it’s impressive for the Mustang to manage its weight penalty with grip despite similarly sized tires.

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