I Buy Auto Parts for a Living. Here's My Honest Take on Gates vs. Aftermarket

My unpopular opinion: buying the cheapest part is usually a false economy

When I first took over purchasing for our 85-person company back in 2020, I assumed my job was simple: find the lowest quote and hit “order.” I mean, that’s what procurement is, right? Get the best price, keep finance happy, move on. Three engine rebuilds later, I realized how wrong I was.

We run a fleet of 22 service vehicles—mostly older LS-based trucks and a couple of turbo diesel vans. Over the past five years, I’ve processed somewhere around 600-700 part orders, give or take. I’ve dealt with everything from Gates timing belts to O2 sensor socket sizes, and I’ve made just about every mistake you can make. So here’s the honest truth: for some parts, the brand absolutely matters. For others, it’s a total waste of money. And if you’re the person signing off on purchase orders, you need to know the difference.

Where I draw the line: timing belts and critical engine components

Let me start with the one part I will never, ever cheap out on again: the timing belt. Back in early 2022, I tried to save $40 on a no-name belt for one of our older trucks. It snapped at 23,000 miles—way before the recommended interval. The result? Bent valves, a cracked head, and a $2,800 repair bill that finance literally questioned for three weeks. I had to explain to my VP why we were eating that cost. Not fun.

Now I only use Gates timing belts. Why? Because they’re the standard for a reason. I’ve installed maybe 15 of them across our fleet, and not one has failed prematurely. Are they the cheapest? No. Are they worth the extra $30-40? Absolutely. It’s a no-brainer when you factor in the risk. A failed timing belt can destroy an engine. A $40 savings isn’t worth that lottery ticket.

“If a part failure can leave a vehicle stranded or cause catastrophic damage, that’s a red flag for cheap alternatives. Pay for the brand.”

Turbocharger hose kits: molded vs. universal

We had an interesting situation last summer with one of our turbo diesel vans. The molded hose on the intercooler piping developed a leak. I needed a replacement fast—like, next-day fast. Normally I’d order the Gates 26216 molded turbocharger hose kit, which is what we’ve used before. It’s a direct fit, pre-molded, and takes maybe 20 minutes to install. But our usual supplier was out of stock, and the dealer wanted double the price and a 3-day wait.

So I made a time-pressure decision. I grabbed a universal silicone hose kit from a local auto parts store—it was cheaper and available immediately. Big mistake. The fit was terrible. I spent two hours trimming and clamping, and it still rubbed against the fan shroud. Three weeks later, it blew off under boost. I ended up ordering the Gates kit anyway. Looking back, I should have just waited the three days or paid the dealer premium. But with the van scheduled for a service route, I panicked. Hindsight is 20/20, but now I keep a spare Gates 26216 kit on the shelf. It’s one of those parts where the molded design makes a real difference—especially under heat and pressure.

Ignition coils for LS engines: aftermarket can work, but watch for red flags

We have three trucks with the 5.3L LS engine. Ignition coils are a common failure point, and I’ve tried everything from OEM Delphi to cheap Amazon specials. Honestly? The cheap ones are a gamble. I’ve had brand-new coils fail within 5,000 miles. But I’ve also had good luck with certain aftermarket brands that are known in the LS community.

The way I see it: if the truck is a beater that rarely leaves town, a $25 aftermarket LS ignition coil is probably fine. But if it’s a critical vehicle that tows or carries expensive equipment, I’ll spend the $70-80 on a genuine GM or Delphi coil. I’m not 100% sure why the cheap ones fail—probably inferior insulation—but the pattern is clear. Frequency hedging: I’d say roughly 1 in 4 cheap coils fail early. That’s not a risk I want on a vehicle that’s 200 miles from home.

O2 sensor sockets: this is where you can save

Here’s a rare case where I’ll actually recommend the cheap option. An O2 sensor socket is basically a single-use tool for most shops. You need the right size—typically 7/8” or 22mm—but the brand doesn’t matter much. I bought a $12 socket from Harbor Freight four years ago, and it’s still holding up. It’s not a precision instrument; it just needs to fit and not strip. So if you’re stocking a shop, don’t overthink it. Buy the cheap one. Save your budget for the parts that actually matter.

Add a leaf vs. helper spring: it depends on how you use the truck

Another decision that comes up a lot with our older work trucks is suspension. One of our F-250s was sagging under load. I looked into adding a leaf spring versus installing a helper spring. The helper spring is cheaper—like $150 vs. $400 for a quality add-a-leaf kit—and it’s easier to install. But here’s the honest limitation: if you’re regularly hauling near max payload, a helper spring is a band-aid. It’ll help, but it won’t restore the spring rate the way an add-a-leaf does. For our truck, which tows a 7,000 lb trailer maybe twice a month, the helper spring was fine. But if it was a daily heavy hauler, I’d spend the extra money on a proper add-a-leaf. There’s no universal “best” answer here—it’s about matching the solution to your actual use case.

Why I’m not just shilling for Gates

I know this might sound like a Gates commercial, but I promise it’s not. I’ve used plenty of aftermarket parts that worked great. The point is that the brand matters most when the failure consequence is high. A timing belt? High consequence. A turbo hose? Medium-to-high (a blowout can leave you stranded). An O2 sensor socket? Almost zero consequence. And an ignition coil? Depends on the vehicle.

Some people might say I’m being overly cautious. Maybe. But after five years of managing this stuff, I’ve learned that the “cheapest” part is rarely the cheapest in the long run. The $40 I saved on that timing belt cost us $2,800. The $20 I saved on a universal turbo hose cost me two hours of labor and a tow bill. Meanwhile, the $12 O2 sensor socket has paid for itself ten times over.

Bottom line: buy smart, not cheap

If you’re the one placing orders for a fleet or a shop, my advice is simple: categorize your parts. High-risk, high-cost-of-failure components (timing belts, critical hoses, ignition components on primary vehicles) should come from a trusted brand like Gates. Low-risk, low-consequence items (tools, non-critical hardware) can be aftermarket. And for everything in between, use your judgment—and don’t be afraid to return something if it feels cheap.

Oh, and one more thing: verify your suppliers. I once bought a “Gates” timing belt from an online marketplace that turned out to be a counterfeit. It lasted 8,000 miles. That’s a red flag I should have caught earlier. Now I only buy from authorized distributors. Honestly, that’s probably the most important lesson of all.