The Boss 429 exists because NASCAR’s rules required Ford to produce 500 road cars equipped with the 429 cubic inch engine it wanted to run at Daytona and Talladega. The engine — designed specifically for high-speed oval racing with a semi-hemispherical combustion chamber configuration that Ford called the Crescent chamber — needed a Mustang body around it to satisfy the homologation requirement. Ford called Kar Kraft, a Michigan-based specialty builder, and Kar Kraft cut the front shock towers of the standard Mustang body to fit the wide engine, moved the battery to the trunk, revised the front suspension geometry, and delivered approximately 859 cars in the 1969 model year and 499 in 1970.

The attribution is disputed, as most famous automotive quotations are, but the sentiment is not: when the Jaguar E-Type was unveiled at the 1961 Geneva Motor Show, it produced a reaction that went beyond the standard admiration afforded to attractive new automobiles. Enzo Ferrari reportedly called it the most beautiful car ever made. The automotive press ran out of superlatives by the second paragraph. Malcolm Sayer, the Jaguar aerodynamicist who shaped the body, was working from engineering principles — the curves were functional, derived from Jaguar’s racing experience with the D-Type — and produced something that looked like it had been shaped by aesthetic ambition rather than calculation.

The debate between 275 GTB purists — those who insist the long-nose, alloy-bodied, six-carburettor 275 GTB/4 is the definitive expression — and those who prefer the earlier short-nose car’s proportions has the quality of all good automotive arguments: it is about something real, it produces no consensus, and both sides have valid points that the other side acknowledges while refusing to concede. The market has taken a position by valuing the /4 variant substantially above the earlier car, but market valuations reflect consensus rather than correctness.

Brake fluid is hygroscopic. It absorbs moisture from the atmosphere through the brake system’s seals and reservoir cap over time. The moisture absorption is unavoidable regardless of driving habits or climate. What changes with moisture content is the fluid’s boiling point — as the water content increases, the boiling point decreases, and when brake fluid boils it converts from liquid to gas, and gas is compressible in a way that brake fluid is not.

Autodelta, Alfa Romeo’s racing arm, produced the Giulia Sprint GTA by taking the standard Sprint GT coupe and replacing most of its steel body panels with aluminum. The result — GTA stands for Gran Turismo Alleggerita, lightened — weighed approximately 745 kilograms, which is roughly half the weight of a modern compact car and 200 kilograms less than the standard Sprint GT it was derived from. Into this lightweight package went a 1,570cc twin-cam four-cylinder that produced 115 horsepower in road tune and upward of 170 in full race preparation, driving through a five-speed gearbox to a limited-slip differential.

The Dodge Charger Daytona is one of the more extreme objects ever to wear a manufacturer’s badge and a license plate simultaneously. The 18-inch aluminum nose cone that replaced the standard Charger’s front end was designed in a wind tunnel at the Lockheed facility in Burbank. The 23-inch rear wing — positioned high enough that the trunk lid could still open — was there not for aesthetics but because the aerodynamics of the standard Charger body at 200 miles per hour produced lift that made the car dangerously unstable. Chrysler’s engineers needed the downforce. They also needed to sell 500 examples to homologate the car for NASCAR. They built 503.

The 1970 model year was the last before emissions regulations, insurance industry pressure, and fuel economy concerns began the systematic reduction of American muscle car performance. Chevrolet, aware of what was coming, produced the 1970 Chevelle SS 454 in the full knowledge that it represented a high-water mark that would not be repeated. The LS6 engine variant — 454 cubic inches, solid lifters, high-compression heads, and a factory rating of 450 horsepower that was understood at the time to be conservative — was the most powerful engine Chevrolet offered in a passenger car in 1970 and arguably the most powerful engine Chevrolet has offered in a passenger car since.

Engine oil is the most important consumable in an automobile and the one whose selection generates the most confident misinformation from people who should know better. The advice circulating in service station waiting rooms, online forums, and casual conversations among car owners contains a remarkable quantity of mythology about viscosity grades, synthetic versus conventional formulations, and the optimal change interval — most of it wrong in ways that range from harmless to genuinely damaging.

The claim that the BMW 2002 invented the sport sedan is made with enough regularity in automotive writing that it risks losing its meaning. It is nevertheless accurate. Before the 2002, performance cars were sports cars — two seats, impractical luggage space, a driving experience that required commitment and sacrifice. The 2002 demonstrated that a four-seat, practical saloon could be as rewarding to drive as a sports car while remaining useful for the everyday purposes that sports cars excluded. The 3 Series, the M3, and forty years of sport sedan development trace directly to what BMW did with the 02 series body and a 2.0-liter four-cylinder engine in 1966.

The new BMW M5 will do zero to sixty in 3.4 seconds. It weighs 2,445 kilograms. These two facts exist in a tension that the M division has spent considerable engineering effort resolving and that no amount of engineering can fully reconcile. The car is extraordinarily fast. It is also extraordinarily heavy, and the M5 lineage — from the E28 original through the E39 that most enthusiasts consider the definition of the breed — was built on the proposition that performance and mass should not coexist if the goal is driver engagement.