Tech & Auto
Here Are The Most Reliable Inline-6 Engines, Ranked
By JUSTIN OWEN
10. BMW M30
First released in 1968, BMW’s M30 inline-6 was so well designed that the manufacturer used the engine for almost three decades.
The M30 proved to be a durable and reliable engine, capable of withstanding modifications to make high levels of horsepower. The engine remains a popular classic among racers.
9. M103 and M104
The M103 6-cylinder engine originated in the mid-’80s when Mercedes released its legendary W124. The company would later introduce the improved M104.
The M103’s reliability was due to its precision engineering. Mercedes-Benz relied on solid build quality with good performance for smooth rides.
8. AMC 4.0-liter
American Motors Corporation introduced the 4.0-liter inline-6 engine with the 1987 Jeep Cherokee, Comanche, and Wagoneer, though its roots trace back further.
The 4.0-liter I6 proved to be a rugged and reliable engine. It featured fuel injection and two valves per cylinder, making it good for 190 horsepower and 235 pound-foot of torque.
7. Twin H-Power
Although Hudson has been defunct for over half a century, its Twin H-Power straight-6 engine is a NASCAR legend.
This 5.0-liter straight-6 flathead engine could be tuned to produce up to 210 horsepower with 260 pound-foot of torque.
6. Slant Six
Although the engine was never a powerhouse, as it was built for economy models, Chrysler’s Slant Six engine produced good low-end torque and was found in many large models.
Owners were generally happy with their reliable slanted engines, but things changed when new emissions laws forced Chrysler to clean it up, causing them to have many issues.