Can You Bring your own parts to the mechanic?

Bringing Your Own Parts to the Mechanic: The Pros and Cons

Most shops won’t install customer parts, and there are very good reasons for that, which I’ll get into below. The shops that will install customer-provided parts usually upcharge the labor to compensate for the lost profit on the parts, and they won’t give you a warranty if your part fails. Overall, you don’t really save money if you bring your own parts to the mechanic.

Why auto repair shops won’t install your parts

Auto repair shops, just like every other service business, make their money on labor profit and parts profit. When you bring your own parts because you found them cheaper online, you’re basically asking the shop to forfeit some profit. Let’s look at why that doesn’t work.

• Customers buy low-quality parts— Customers who want to save money by supplying their own parts usually buy the cheapest parts. Low-quality parts often don’t come with new fasteners or associated parts like gaskets, belts, or sealants.

So, the shop quotes a price, removes the old part, and then finds you ordered the wrong part, or it doesn’t fit properly, is missing fasteners or associated parts. So you run back to the auto parts store to exchange the part and round up the missing parts.

In the meantime, the shop’s bay is tied up, and the clock is ticking. A tied-up bay means lost money, which is a huge deal for a small shop. If the shop bills you for the extra time involved, you’ll scream bloody murder and give the shop a bad online review.

If, on the other hand, the repair goes well, but the cheap part fails early, you’ll immediately blame the shop for messing up the installation and give the shop a bad online review. Either way, the shop gets screwed and has to deal with bad online reviews, all while losing profit on the repair.

Customer-provided parts cause nothing but aggravation for shops

• Installing customer-provided parts is a money-losing proposition— As I mentioned earlier, shops make their living on part profit and labor profit. When you bring your own parts to the mechanic, you’re effectively asking them to lose money on your job. Why would they do that?

You’re not getting ripped off by the shop’s parts prices

Just because you found the part cheaper online doesn’t mean the shop is ripping you off. Like every other service business, auto repair shops buy their parts locally and mark up the price to the customer. That’s standard in every single service business. Plumbers, electricians, HVAC installers, and carpenters all buy the parts and all service businesses add a parts markup. Parts markup varies in the auto repair but generally runs 66% to 100%, which is in-line with every other retail service business.

• Parts markup on a new furnace—In 2022, the typical installed price for a baseline 60,000 Btu furnace and 2-ton AC unit is around $8,900. The company’s cost for the furnace, evaporator coil, condensing unit, refrigerant, tubing, sheet metal, piping, and city permit averages about $3,300. It takes two workers about 12 man-hours to remove the old furnace and install the new setup.
• 12 hours @ $125/hr =$1,500 – actual fully loaded hourly cost of $55/hr ($660) for a labor profit of $840 (97% markup on labor).
• Salesperson’s commission @ 10%= $890
$8,900 selling price minus $1,500 labor, $890 sales commission, and $3,300 parts cost =  $3,210. $3,210 ÷ $3,300 = 97%

• It takes time for the parts to arrive— Shops usually order from the closest auto parts store. But many times they have to get the part from another store. If the parts store is really fast, they can get the part to the shop in 20 minutes. But in most cases, it’s a 45-min to an hour wait. That wait ties up the service bay. Parts profit is what pays for the waiting time.

But you found the same part online for less. So what?

Lots of online sellers sell their goods for much less than brick-and-mortar stores. That’s nothing new; it’s been that way for decades. But as I said earlier, shops don’t buy parts online, so the price you find online is irrelevant. When a shop needs a part, they need it right now, not three days from now.

The strut assembly price on the left is from Rockauto.com. You order the part and install it yourself. The price on the right is the price for the same strut from NAPA. The shop applies their discount and then adds their markup

What about the shops that will install the parts you bring to the mechanic?

In most cases, they’ll either up their normal hourly rate to compensate for the lost parts profit, or they’ll adjust the quote upwards to compensate for the lost parts profit. Either way, they’re not going to lose money on you. If the part you ordered doesn’t fit properly or is missing parts, you’ll be billed additional at the shop’s hourly rate for the time needed to fix the problem.

Here’s the bottom line on whether it’s ok to bring your own parts to the mechanic

What you’re proposing is no different from a scenario in which you buy a steak at a meat market, bring it to a steak house, and offer to pay only for the time they grill it. They’d boot you out the door for asking for something so outlandish. It’s just as outlandish to bring your own parts to the mechanic and offer to pay only for the labor to install it.

©, 2018 Rick Muscoplat