Why do automakers design engines, too?

Generally, auto manufacturers install their own engines in their own cars (although some diesels are exceptions…Cummins-powered Dodge pickups come to mind.) This is general practice for mororcycles, as well.

However, commercial trucking generally uses engines made by others. Same with small-engines, and (I think) marine. Aviation, too, NEVER makes engines in-house (except I think Honda made an entire bizjet at some point?)

Is this a matter of economies of scale, history, or what? After all, plenty of auto parts are outsourced (no “Ford tires”) without qualm.

It takes a lot of people and a lot of industry to make big products. Many jet engines are leased rather than owned outright.

It isn’t only the engines that come from outside the truck company. All the running gear comes from everywhere else too. There are many choices. A truck for one job can be totally useless for another.

Automakers design and build their own engines–because they can. But often a lot of parts on the engines they build are outsourced to suppliers. Eg. Melling makes oil pumps, pistons aren’t necessarily made in house, no one likely makes their own bearings, etc. And automakers often have cooperative partnerships with each other–some Saturns had Honda engines, Chryslers had Mitsubishi engines (Chrysler’s engines were better), I think older Taurus SHO models had Yamaha designed engines, etc.

Basically automakers will do whatever is the most cost effective, depending on whether or not an outsourced solution exists. If there were companies making engines suitable for autos, they would be sought and purchased. The trucking industry is a little different, as Cummins for example makes engines for a ridiculous number of applications, from stationary pumps and generators to front end loaders, to pickups. So they already have a mostly “off the shelf” solution that just needs some tweaks. Since autos are more single purpose and the engine is more tailored to fit under the hood, etc., it’s not cost effective for an outside supplier to design and build an engine in most cases–they wouldn’t profit in the development of a motor to work on a single platform, meet CAFE, etc. Though I’d expect this to slowly change. Other drive train components like axles, driveshafts, gear sets, those are sometimes made in house, but very often designed and built by top tier suppliers to automakers’ specs. Even frames for vehicles are sometimes made by suppliers. That Ford F150 you’re driving? Ford didn’t make the frame. At least not a big chunk of it. As more and more technologies go into vehicles to make CAFE standards and provide luxuries like Internet connectivity, you’re only going to see more and more of your vehicle not made in house, but a hodgepodge of cooperative efforts.

In the 1920s & 1930s, a fairly large number of independent makes used engines manufactured by Continental Motors (no, not the Ford division!), and–in fact–use of Continental engines was more or less the norm for the smaller auto companies.

Add marine engines to outsourced components as well. Many John Deere tractor components, motors and entire tractors are made in India and Japan and have been for decades. The entire Scion FR-S is made by Subaru. You would think Toyota wouldn’t have to depend upon smaller Subaru to supply a car. But if car companies out source entire cars, it really isn’t that unusual to think they would do the same with components.

There are far more truck manufacturers than truck engine manufacturers. Truck engine development requires huge sums of money and a typical truck manufacturer can’t afford that. So Volvo, Caterpillar, Cummins and Mercedes are major manufacturers who sell to
truck makers…The same is true for transmissions. Marine engines, same thing . Worldwide there is only a handful of large marine diesels but many shipyard. Sultzer, B&W of Denmark, and several German companies come to mind.

With respect to aircraft, the same story, but for different reasons. Plane makers are officially called “airframe manufacturers”. Their skills are in aeronautics, not in power plant design. That development is even more expensive, and worldwide there are only a few with very deep pockets., such as GE, Pratt & Whitney, Rolls Royce & ABB. Bombardier of Canada is the third largest plane maker after Boeing and Airbus, but does not have any engine manufacturing capability. And wisely so.

All engine development is very specialized now in view of emissions and fuel efficiency. Even car makers now share development, such as the Chrysler V6, developed with Citroen of France and Volvo. Fuel injection systems are mostly Bosch and Japanese.

This trend will continue and apply to other specialized equipment that requires a lot of engineering.

“Plane makers are officially called “airframe manufacturers”. Their skills are in aeronautics, not in power plant design.”

That has proven to be true in practice, when an aircraft manufacturer–such as Ford, which had much power plant know-how–outsourced their engine supply to another company. Despite not having been previously known for their aeronautic designs, Ford built the famed Trimotor, with power supplied by 3 Wright radial engines.

Not all auto makers do design or have designed all of their own engines. For a while, at least, Saturn was using a Honda engine in one of its cars. I think it was the Vue. Unfortunately, having a Honda engine didn’t make it a better car.

One of the odder pairings: Lotus has used a number of Toyota engines…

It’s hard to make any money if you must buy your engines from a third party…Also, if your engine supplier has production problems, your car business is toast…

It’s not just engines that’s outsourced. My brother-in-law was a General Manager at the New Process Gear (owned by Chryco) plant in Syracuse before he became plant manager at one of Chryco’s plants in Michigan. In the 80’s trough the 90’s they were the largest producer of transfer cases in the world…and less the 40% went to Chryco. Most were going to GM…Land Rover and BMW also bought from them.

And let’s not forget Rolls Royce using GM transmissions. The list is endless.

The question of “Buy or Build?” is asked on a continuous basis at any place that makes things even after a product is released for sale and has been in production for some time. The decision is based mostly on cost, technological ability (can we do it?) and ensuring a reliable supply. Some truck companies may have made their own engines at one time but the decision to buy made often enough has left them technologically stranded so that it would require too much money to get back into the engine building business. There are enough engine vendors for them so that a reliable source is not a problem.

It could be said that a car company must use in-house engines for customer satisfaction including pride of ownership but a truck is just a tool.

Ford just went through that for their diesel engines in pickups - they had used IH, now they’re using their own, I think.

Aren’t the Ford Powerstrokes derived from IH designs?

As in, FoMoCo used the IH design, and liked it so much they purchased the “intellectual property” from IH/Navistar, then atarted making revised versions themselves.

It’s not just engines.
IIRC, the hybrid technology that Ford uses is licensed from Toyota.

I don’t know about the designs, but I thought Ford had been buying from IH, now they make them in house.

As for the hybrid technology, there was some sort of exchange with Toyota, but the majority of the tech came from Toyota, like VDC noted.

In my mind…having an in-house production of engines is the surest way of maximizing profits. That’s probably why they do it.

For carmakers it’s really a matter of resources, both brains and money. Small carmakers like Kaiser in the 40s and 50s used the Continental Red Seal engine, also used by Jeeps.

Hyundai initially used Mitsubishi engines in their Pony model, about the only thing good in that car.

At this stage only the major car builders can afford to develop entire engines; GM, Ford, Volkswagen/Audi, Mercedes, Renault/Nissan, BMW, Toyota, Honda, Mazda, Chrysler/Fiat, Hyundai/Kia; all the rest have to do it in cooperation with others, and then build them in their own plants with local modifications.

Even GM had to streamline engines - each division used to have multiple engines, now there are far fewer designs shared across all divisions. They got in trouble years ago putting the Chevy engine in Oldsmobiles, I think. Commonplace now.