How Long Do You Think It Takes to Make a Car?
How Long Does It Take?
Let's Look Back a Bit...
Did you ever wonder how long it takes to make a car? It is way less than you think. But before we look at the actual numbers let’s look at some history and then agree on some definitions.
The best example of old-time automobile manufacturing is the Model T. Henry Ford is credited with revolutionizing the automobile industry, but he did much more than that. He revolutionized manufacturing in general—across all industrial categories. He did this by standardizing parts, limiting options, and choosing materials that were amenable to quick assembly. Most importantly, he developed machines that were designed to either independently accomplish tasks or assist workers and speed up the process. Was he successful? Let’s put it this way. He and his staff came up with systems that reduced the over all assembly time on a Model T from 12.5 hours to 93 minutes. That is a pretty impressive 87.6% reduction in production time.
Things Have Changed
How does that compare with today’s assembly time? It is not a fair comparison. Today’s vehicles are a good bit more complicated than in 1925. They are expected to be safer, handle speeds that were unheard of in 1925, and last for years and years.
One of the things that Henry Ford’s factories did that is even more relevant today is the use of preassembled parts. So, let’s agree on some definitions. When I am talking about how long it takes to “make a car.” I am referring to the amount of time it takes to assemble all the parts that have been brought together to the final assembly plant. It assumes that there are many assemblies or sub-assemblies that are coming to the plant ready to install. That seems to miss out on a great deal of the overall manufacturing process, but it still includes a great deal of work.
The bodies are stamped out, interiors installed, wiring harnesses put in place – it is a big job. Toyota estimates that its SUV’s have about 30,000 parts. Some may come to the final plant as part of an assembly ready to be integrated into the new car. Some comes in as raw materials that are fabricated on the spot.
Modern Technology at its Best
Making the Body
A good bit of the automobile comes to the final assembly plant ready to be installed. Things like seats, radios, wiring harnesses, and motors to run all the various power accessories all come to the assembly plant ready to install. The body itself, though, is usually made at the final assembly plant and guides much of the assembly process.
The body assembly is amazingly complex. Steel of many different types is stamped and molded into shape. The different materials are carefully placed according to the engineers' design and provide for things like crumple zones, penetration protection and cabin integrity. The various materials are robotically welded into a unit that superficially looks like a car, known in the industry as a "white body."
The white body is then inspected both by laser-guided systems and by hand. From there it gets cleaned, coated with an undercoat, dried and re-inspected. If it passes inspection, it get its color coat of paint, another drying, and then clear coating. The final step is a few minutes in an oven to bake the finish and harden the paint. Only then does it enter the production line to be mated up with an interior, drivetrain, and remaining parts.
So, we have cheated a bit by only counting the time it takes for the final assembly. It would be impossible to track the production time on every screw, nut and bolt.
There is a great deal of variability in assembly time. The entire process varies from car to car and manufacturer to manufacturer. Cars with lots of hand work, like a Rolls Royce can take up to six months to produce. Rolls Royce has very limited sales and the slow production time is not an issue. Besides, many people expect the slow production speed and assume it allows for a greater level of quality and personal attention.
What is amazing is the speed at which high production cars and trucks can be turned out. Toyota releases a substantial amount of information about their production procedures and figures. They estimate that a well appointed car, truck or SUV takes about 17 to 18 hours to assemble. Other manufacturers have similar numbers. Some lesser appointed vehicles can be assembled as quickly as 11 hours.
The surprising part is that they are coming off the production floor about one vehicle every 45 to 90 seconds. The largest plants are turning out over 400,000 cars a year.
The Past and the Present
I know what you are thinking. Henry Ford was popping cars out with an assembly time of 93 minutes and that is way more impressive. But is it really. I think it is hard to compare. What he did was amazing. He was a true groundbreaker that changed manufacturing and modern life for us all.
Granted the speed at which he could turn out a car was - and is - impressive. But let's make sure we are comparing apples to apples.
The car Henry Ford was producing had about 1481 parts. The current Toyota SUVs have about 30,000 parts. So instead of looking at total assembly time, let’s look at the number of seconds it takes to install a part on a Model T and a modern car. The Model T with its impressive 93-minute assembly time, required an average assembly speed of 3.76 seconds per part. Today’s Toyota manufacturing process is way faster. They are averaging 2.04 seconds per part.
Finally, what do you think takes longer to install a 2-speed transmission with cotton and wood linings, or an 8 speed all-wheel drive transmission with as many parts as the entire Model T?