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PSA: Be Safe With Carburetor Cleaner, Too

Recently, I wrote about how brake cleaner can be hazardous if not used correctly, and how you should take safety precautions when using it. One of our readers had an insightful comment on the piece.Now, I think it’s debatable that carburetor cleaner is more hazardous...

The Real Meanings Behind OBD-II Diagnostic Trouble Codes (VIDEO)

Description When the check engine light (CEL) pops up and your OBD-II scan tool displays a code, that’s only the start of the diagnostic process. By breaking down the structures used to create DTCs, you can learn how to “decode” beyond the simple descriptions...

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Hybrid A/C Compressor Oil-ASE Practice Question (VIDEO)

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Troubleshooting a “No A/C Compressor Engagement” Fault

As the weather warms, more and more of your customers will be switching over their HVAC control settings to “max A/C”. If the system doesn’t respond by blowing that refreshing cool air into their faces, they will show up at your door to find out why. When faced with...

Is the Oil Change Interval in a Vehicle’s Owner’s Manual Always the Right Choice? (VIDEO)

Description When choosing an oil change interval for a car or truck, some technicians follow the guidelines in the owner’s manual, while others will suggest a conservative figure such as every 3,000 miles. Pete Meier explains how vehicle usage and oil/filter quality...

Diesel Engines and Racing

Nearly every conceivable version of the internal combustion engine has made its way to the Indy 500. But it was a 1931 entry of a rather unusual type that made it into the record books as the first to complete the entire 500-mile race without a pit stop. That entry...

Recovering A/C Refrigerant-ASE Practice Question (VIDEO)

Description Technician A is preparing to recover the refrigerant from a customer’s vehicle. All of the below are steps he should take when performing this service EXCEPT: A) Test for the presence of sealant in the vehicle systemB) Identify the type of refrigerant the...

Shifting Gears

What does horsepower really mean? (VIDEO)

by Andy Greaser | Dec 17, 2024

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Horsepower is a strange measurement, isn’t it? Think about it. When was the last time you used a horse for any kind of work or travel?

Like candlepower, the original horsepower attempted to express the output of a newer technology in comparison to its predecessor. Today, horsepower is one of the most common metrics we use to quantify vehicle performance, yet most of us in the auto repair industry have no experience with real horses at all. And even if we did, how would we meaningfully measure the work potential of a horse? How might that measurement of power translate to mechanical devices?

Thankfully, a clever guy named James Watt did the math for us over 240 years ago while developing steam engines that would kickstart the Industrial Revolution. This old Chevrolet video from 1937 does a fine job of explaining Watt’s journey to the earliest version of the horsepower measurement we know today. (The informational part of this video starts about two minutes in.)

Later advancements in power measurement made Watt’s horsepower obsolete with new variations like metric horsepower and imperial (mechanical) horsepower, but it is fitting that the International System of Units (SI) uses the watt as its standard for the same type of power measurement today.

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