The 13.5-Liter Straight-Six That Made the 2JZ Look Like a Toy
Before balance shafts and turbochargers, American luxury giants built inline-sixes so large they made modern muscle look modest — and one still holds a Guinness record.
When Six Cylinders Meant Eleven Liters
The inline-six is usually the sensible choice — smooth, compact enough for a sedan, and easy to package. But in the early 1910s, some American manufacturers decided that "sensible" meant "as big as a boat engine." The Oldsmobile Limited of 1910 started with a 505-cubic-inch straight-six, which was already enormous. Then in 1912, Oldsmobile engineers added more than 200 cubic inches, bringing the total to 707 cubic inches — 11.58 liters. The engine used a T-head layout with two cylinders per casting, a 5-inch bore and a 6-inch stroke, yet it produced just 60 horsepower. The point wasn't speed; it was effortless torque for pulling a 138-inch-wheelbase limousine on 42-inch wheels. Only about 140 were built in the final year, and one sold at auction for $5 million in September 2025, making it the most expensive Oldsmobile ever.
The Peerless and Pierce-Arrow Rivalry
Cleveland's Peerless and Buffalo's Pierce-Arrow were locked in a battle for the largest production engine, and they ended up nearly tied. The Peerless Model 60 of 1912 packed 824 cubic inches (13.5 liters) with a 6-inch bore and an 8-inch stroke, while the Pierce-Arrow Model 66 grew to 825 cubic inches (13.52 liters) in 1913. Both used T-head valvetrains, and displacement figures were so close that they're often cited within a single cubic inch of each other. The Peerless cost $6,000 new, and only 57 examples were built by 1914. The Pierce-Arrow, by contrast, managed a production run of 1,250 cars between 1910 and 1918, with wheelbases up to 147.5 inches. Pierce-Arrow's engine red-lined at just 1,500 rpm, producing nearly 100 horsepower — but the torque is what mattered, letting the car haul heavy coachwork without strain. Guinness recognizes the Pierce-Arrow as having the largest engine in a production car.
Why Did They Build These Monsters?
The answer is simple: there were no highways, and the roads were terrible. These cars were built for the wealthy who wanted to cruise at 40 mph without the engine working hard. Displacement was the easiest way to get low-end torque, and there was no tax penalty for it. The Locomobile Model 48, built from 1911 to 1929, started at 429 cubic inches and grew to 525 by the late 1910s, with a stroke increase from 4.5 to 5.5 inches. It made only 70 horsepower initially, but the engine was so smooth and quiet that it attracted owners like William Wrigley, the chewing-gum magnate, and members of the Vanderbilt family. The car's 18-year production run without major changes was a testament to its design. But these engines were also heavy — the Bentley 8 Litre of 1930 used a magnesium-alloy crankcase to keep weight down, and it still needed a chassis with a 156-inch wheelbase to carry it.
The Legacy: Why Collectors Pay Millions
Today, these early giant sixes are prized not just for their rarity but for their engineering audacity. The Pierce-Arrow Model 66 is described by RM Sotheby's as 'the Holy Grail' of Brass Era cars. The Oldsmobile Limited's $5 million auction price in 2025 shows the demand. But the legacy isn't just about auction records. These engines influenced the development of modern truck diesels, which rely on the same long-stroke, high-torque philosophy. They also proved that smoothness doesn't require exotic counterweights — just six cylinders firing in order. Modern inline-sixes are praised for their refinement, and they owe a debt to these early giants. At less than a quarter the size of the Pierce-Arrow, the Toyota 2JZ produces far more power per liter. But for sheer displacement and the torque that moves a limousine, nothing has ever topped these early monsters.