V6 vs. Inline 6: Pros and Cons

For quite a few years after the invention of the automobile, engines came in only one fashion – all cylinders lined up in a straight line. It wasn’t until the early 1900s that Rolls Royce and Cadillac began manufacturing the first V-shaped engines. Later, Henry Ford designed and patented the first flathead V8 in 1932. Over the years there have been purists on either side who argue the pros and cons of both types. Today, the most commonly made duo of V-shaped and inline engines is the 6-cylinder. Both are still available in current automobiles and both have their advantages and disadvantages. Before deciding which one is best for you, let’s take a look at the good, the bad and the ugly of both.

The V6 Engine.

Pros: More compact, less costly to produce, allows for added interior space.

Without the V6 engine, cars would probably still be roughly the size of battleships. The increasing demand for interior space and a more maneuverable vehicle make the V6 a solid choice for manufacturers. They can fit the same power (or fairly close to it) engine in half the space, allowing for the extension of interior legroom and good bit of added front end snipped off the nose. They also take less overhead to produce. This, in theory, should bring added savings to the buyer. That’s not always the case, but there’s nothing wrong with dreaming.

Cons: Slight loss of power, susceptible to vibration, harder to service.

Since there are an odd number of cylinders per side, the V6 is more susceptible to vibration due to the primary dynamic balance. This, unfortunately, cannot be remedied. Even inline-5 cylinder engines have this issue due to the odd number of cylinders. The V6 also experiences a slight loss of power on the down stroke. This can cause the engine to run rougher than its straight-line counterpart. And, of course, since these engines are smaller, manufacturers love to cram them into tight, little engine compartments, making them a real pain for technicians who need to get their big hands into spaces that can only be reached by elves, fairies and other tiny mythological creatures.

The Inline-6 Engine

Pros: No vibration, less complex, more powerful.

Traditionally, the inline-6 has been a more reliable engine. Whether this is due to dynamic balance or just the simplicity of design is a mystery. What is true is that they are far easier to work on, and not just because of the added space in the engine compartment, though that helps. The firing order of an inline can only go one of two ways, either from front-to-back of the engine or back-to-front. Since the cylinders are all lined up in an even number, vibration is also nullified. They have a reputation of being very sturdy engines as well. Some of the older Dodge inline-6 cylinders would leak up to two quarts of oil per week and still run for hundreds of thousands of miles (as long as you kept filling them up).

Cons: More expensive to manufacture, less interior space, don’t fit into most newer cars.

The added need for more space inside the car, as opposed to where you work on it, has left the inline-6 as the second-rate choice for many car buyers and manufacturers. It is also more expensive to produce which can add to the sale price of the vehicle. For reasons unknown, several models of inline-6s are more susceptible to oil leaks, even after being resealed. Despite the added cost, they don’t typically add to the resale value either.

No matter which route you go, gas mileage differences are negligible. You’d need to be a mathematician to figure out the exact difference and even then it wouldn’t really have been worth the time to see the couple of cents difference. It basically just comes down to personal preference. If you enjoy the added comforts of legroom and interior space, stick with the V6. If you plan on working on your own vehicle or are just willing to trade a little space for some added power and reliability, you may want to check into one of the few cars left out there still equipped with the inline. Either way you go, you’ll have arguments on both sides of the fence as to whose is better.

Here’s a list of all V6 cars and here’s a list of all 6 cylinder cars.

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