In Automobile design, an MR or Mid-engine, Rear wheel drive layout drives the rear wheels with an engine placed just in front of them, behind the passenger compartment. In contrast to the rear-engined RR layout the center of gravity of the engine is in front of the rear axle. This layout is typically chosen for its near-ideal weight distribution. The mid-engined layout does, however, use up a lot of space, making it impractical for any but two-seater sports cars. Also this layout is not considered a 100% success. Mainly because when the weight is in the rear of the car and makes the car rear heavy. Though it is sometimes advantageous to have weight in the rear during cornering it makes entry a lot more difficult as front tires got less traction resulting in a slight understeer and at the exit the rear tends to create heavy oversteer

Early cars using the MR layout included the Zündapp Janus (1957), Lotus Europa (1966), Porsche 914 (1969), the Lamborghini Miura (1966), and the Ford GT40 (1966). The popularity of the term grew after Toyota used it on their MR2. Its space-inefficiency means that it is still only used in sports cars (or supercars) such as the Ferrari Enzo Ferrari, Honda NSX, Lotus Elise, and Pagani Zonda.

See also:

• Front wheel drive
• All wheel drive
• Rear wheel drive
• FR layout
• RR layout
• FF layout
• List of MR Cars