The fiberglass bodywork attached to the aluminium chassis was similar to the M8F, maintaining the "Coke bottle" design,[5] but with the addition of ducting on the side to feed the radiators.

Improving on the recently developed cross-drilled brakes from the previous season, grooves were machined into the discs to prevent outgassing.

Further problems appeared at Road Atlanta, where aerodynamics led to Hulme's car becoming airborne and flipping while following closely behind one of the Porsches.

Although Hulme's car was destroyed and had to be replaced by the third M20, Denny was quickly able to recover and earned his second victory of the season at Watkins Glen International, followed immediately by Revson in the other McLaren.

[4] After maintaining a close battle with Porsche in the first four races, McLaren saw the rest of the 1972 championship hopes slip away as numerous mechanical problems, mostly related to their Chevrolet motors, left them unable to finish several events.

Hulme earned another second-place finish at Edmonton, his car reliability was no match for that of Penske-Porsche driver George Follmer.

Hulme was able to secure second place over the troubled season, but earned only half the points total that Follmer amassed.

Patrick won the final race of the season at Road America after the dominating Shadows suffered mechanical problems.