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A Call For Automotive Parts Standardization

Here is a call that will certainly fall on deaf ears: We need a organized and concerted effort to standardize commonly replaced parts. OEM parts proliferation is running rampant and is only getting worse with each new model year which is creating bigger and bigger headaches for those of us in the parts and service business.

The car companies are all crying about lower profits and are putting the squeeze on their parts vendors to cut prices (or else!). I say one of the best ways to accomplish such price reductions is to quit making the suppliers redesign and re-engineer parts that should have been standardized long ago. It makes no sense to redesign and spend thousands and thousands of dollars on new tooling to customize a part that really does not have to be customized (that's "optimized" in engineering lingo).


For instance, there is no engineering reason why all cars cannot share a common oil filter. But we cannot even get the vehicle manufacturers to standardize their own filters within their own product lines, let alone come up with some industry-wide standard.

When I say a "common" oil filter, I mean the same sized can with the same threads and gasket. The filter manufacturers can do anything they want inside the can with different filter media to achieve product differentiation. But imagine what a standard oil filter would achieve. It would eliminate the need to stock dozens of different filters which currently come in many different diameters, lengths, gasket and thread configurations. It is crazy and serves no good purpose except to require car dealers, warehouse distributors, jobbers and service outlets to stock a lot of unnecessary inventory.

A common sized oil filter would also eliminate the need for half a dozen different sized oil filter wrenches to change the filter.

Here's a even more radical idea: how about a standardized location for the oil filter? This will never happen because of differences in engine configurations, but we should at least have some kind of industry standards or criteria that define what constitutes an "acceptable" location for the oil filter. The primary criteria should be serviceability. On many engines, the oil filter is difficult to reach. On others, the filter is located directly over a crossmember, the steering rack or linkage, exhaust pipe, starter motor or halfshaft so it dribbles oil all over and makes a royal mess when it is changed.

Any engineer who violates these standards should be forced to work in a quick lube and replace his filter design at least 1,000 times as punishment for his stupidity.

There is no engineering reason why all oil drain plugs can't be a common size.


There is no engineering reason why three or four basic battery sizes cannot fill all cars and light trucks. We don't need a zillion different group sizes and terminal configurations. The aftermarket can consolidate replacement batteries down to a few, so why can't the OEMs?

There is no engineering reason why three or four basic alternators can't be used on all cars and light trucks. A few basic amp ranges plus an indexable mounting should allow a handful of alternators to fit virtually any application. What's more, alternators should be mounted so they are protected from road splash yet be easily accessible so they can be replaced without having to drop the exhaust system, remove motor mounts or other belt-driven accessories. Consumers are the ones who end up paying for the added labor on such hard-to-replace components.

The list goes on and on. There is no reason why any of the following parts can't be radically consolidated down to a few part numbers common to most vehicles:

  • Air filters
  • Fuel filters
  • Oxygen sensors
  • Spark plugs
  • Fuel injectors
  • Fuel pumps
  • Starter motors
  • Radiator caps
  • A/C compressors
  • Brake pads
  • Brake shoes
  • Brake calipers
  • Wheel cylinders
  • Master brake cylinders
  • Headlamp bulbs
  • Taillamp bulbs
  • Lug nuts
  • Wheel lug patterns (one common 4, 5, 6 and 8 lug size)

The only valid argument against standardizing many of these parts is the claim that it would inhibit innovation and product differentiation. My response to that is BULL----!

When someone is shopping and comparing a new car or truck, they are looking at features, styling, what options are included and the price. If they find a vehicle they like, their buying decision usually hinges on two things: does it seem like a good value for the money, and can they afford it? They could care less if the parts are standard or not, until it comes time to get the vehicle serviced. Then they discover it requires some oddball part that costs a fortune or is hard to get. They end up paying a premium for the engineering excesses of the vehicle manufacturer, and may be inconvenienced if the part is not something that is normally stocked or is on back order. And who does the motorist get mad at? Not the car manufacturer who specified and designed the oddball part but the service facility who has to fix it.

Remember the oddball sized TRX wheels that Ford introduced back in the 1980s on some Mustangs? For most vehicles, it is cheaper to buy a new set of wheels and tires than to buy the special TRX tires required to fit these wheels. And who ends up paying for it? The poor consumer, that's who.

Ever price a replacement starter for a Toyota Previa? They list for over $600. Why? Because they are an oddball design that does not fit anything else. What's more, the number of Previas built has been so small that it does noy make economic sense for anybody in the aftermarket to tool up and built a less expensive replacement starter.

As I said earlier, parts suppliers can differentiate their products all they want within the design limits of an interchange standard. They do it now. You can have two spark plugs that are physically interchangeable yet have different heat ranges, electrode configurations and electrode materials.

With brake pads and brake shoes, there would probably have to be a common size for small cars, another for medium cars, another for large cars, and another for light trucks and SUVs. But within each group, brake manufacturers could use various grades of friction material to achieve certain levels of brake performance.

While I'm preaching on my soapbox, I would also like to vent at OEM engineer who design parts that are service nightmares. Their main design criteria often seems to be ease of assembly at the car factory, not easy of serviceability when the part fails and has to be replaced. There are too many examples to list here, so I'll just give you one of my unfavorites: the water pump on a Ford Probe 2.2L.

The pump is located on the engine under the timing belt. The timing belt is under a two piece plastic cover, which requires removing the crank pulley, alternator belt and A/C and PS pump belts.

The timing cover is also under the right side motor mount. The motor mount is located so close to the strut tower that the three bolts that attach it to the block are nearly impossible to loosen. There's barely enough room to get a socket on the bolts, and almost no room to leverage them loose. It is a three hour job at least to change this pump (I know because I've done it!).

The engineer who designed this setup obviously never turned a wrench in his life otherwise he would have realized that his wonderful cost-efficient design is a royal pain to fix! The pump could have been mounted just as easily on the side of the block to make it more accessible.

Unfortunately my rantings and ravings won't change the situation one bit. Some say the main reason why the OEMs have so many different part numbers is to create a captive parts market for themselves and to thwart competition from aftermarket parts suppliers and rebuilders. Others insist it is all done innocently to "optimize" performance or durability, to reduce manufacturing costs or to make parts easier to install on the assembly line (the so-called "systems" approach where various parts are preassembled into a larger assembly).

Regardless of what the real answer is, the only thing that will change current OEM engineering practices is pressure from the parts suppliers who are being squeezed to reduce costs. Their comeback should be, "Fine, you want to reduce costs? Then do it by standardizing parts so we don't have to spend a fortune re-engineering and retooling every part you buy." The suppliers have to tell the OEMs that if they want price reductions, they'll have to settle on common designs and stick with them for a reasonable period of time. Unless there is a compelling engineering reason for requiring a redesign, an oddball design or a unique design, the OEMs should use common off-the-shelf components across as many different model applications as possible. Then and only then will life get better for service technicians who have to fix today's vehicles, and for the parts manufacturers, distributors and suppliers who stock the replacement parts.

Perhaps the best forum to address this issue is through the Society of Automotive Engineers (SAE). Maybe they can convince the corporate bean counters that standardization is a great way to save money.


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Total messages: 1

posted by: Roger on Wednesday, September 19, 2012 at 10:34 PM
Your concept doesn't go nearly far enough. Think about it - think about the driver and passenger interfaces with the vehicle. All manufacturers design for a range of occupants within the widely accepted range of human dimensions. Why, then, do we need thousands of different seat designs, and steering wheel designs, and most other parts of the human-machine interface? Yes, we don't want to "MacDonald-ize" home furniture. But the environment inside a vehicle, a pod for transportation, is different. Imagine the savings of having standardized occupant interfaces - we could go to an "Ikea" type system where you could customize as you please. Really, even dimensions and shapes of the occupant space inside vehicles could be standardized. How many different ways can you design a car floor, interior door panel, steering wheel, or seat???? And don't get me started on the ridiculous world of car stereo interface designs... What is the matter with the typical, fairly standardized computer media player design on a touch screen??