OEM vs Aftermarket Parts: When Each One Makes Sense
We sell both. We stock both. And we get asked which one to buy at least 20 times a day. Here's the honest breakdown from a parts house that doesn't have a horse in the race.
What "OEM" actually means
OEM stands for Original Equipment Manufacturer — meaning the part is made by (or for) the company that made the equipment. A genuine Honda carburetor for a GX270 was either made by Honda or made under Honda's supplier program with their specs and quality control.
OEM parts come in branded packaging with the original part numbers. They usually carry the longest warranty (often 1 year vs. 90 days for aftermarket). They typically cost 30-100% more than aftermarket equivalents.
What "aftermarket" actually means
Aftermarket is everything else — independent manufacturers making parts to fit the same application as the OEM part. Quality ranges from "indistinguishable from OEM" to "complete garbage." The trick is knowing which manufacturers to trust.
Reputable aftermarket brands you'll see on our shelves:
- Stens — Mid-grade, broad coverage of small engines
- Rotary — Strong on Briggs and Honda commercial parts
- Donaldson — Excellent filtration; many fleet owners prefer over OEM
- PIX North America — Premium V-belts and cogged belts
- Walbro / Zama / Tillotson — These are themselves OEM suppliers; their "aftermarket" parts are often the exact OEM parts in non-branded packaging
Where OEM is worth the money
1. Internal engine parts
Pistons, rings, connecting rods, crankshafts, cylinder sleeves, valve trains. These have tight dimensional tolerances and any deviation kills the engine. Always go OEM. Aftermarket internals are a recipe for repeating the repair.
2. Carburetors on EFI-adjacent equipment
If the equipment has an electronic engine controller (newer commercial mowers, EFI variants of Honda GX, etc.), buy OEM. The carb is calibrated to the ECU's expectations.
3. Safety-critical parts
Brake components, hydraulic relief valves, pressure-bearing castings. Pay for OEM peace of mind.
4. Equipment under warranty
If a warranty claim depends on using genuine parts, don't risk it. Use OEM for any service item until the warranty expires.
5. Ignition coils (often)
OEM ignition coils tend to last significantly longer than cheap aftermarket. The pickup-coil and high-tension wire quality matters more than people realize. Mid-grade aftermarket from reputable brands (Stens, etc.) is fine; the $8 Amazon special is not.
Where aftermarket is usually fine (or better)
1. Filters
Air filters, oil filters, fuel filters. Donaldson, Wix, Baldwin, and similar premium aftermarket filters are often manufactured in the same factories as OEM filters. The OEM markup is pure margin.
Exception: for diesel emissions equipment (DPF, DEF systems), stick with OEM. Aftermarket filtration spec can affect emissions performance.
2. Belts and pulleys
V-belts, cogged belts, drive pulleys. PIX, Gates, Bando — these are belt manufacturers, not equipment makers. The OEM belt was probably made by one of them anyway, then re-branded with a markup. Aftermarket here is the smart play.
3. External hardware
Bolts, washers, nuts, springs, clamps, brackets. Buy by spec (metric, grade 8, M8x1.25 etc.) not by brand. Save the money.
4. Spark plugs
NGK and Champion spec sheets cover almost every commercial engine. Buy the correct heat-range plug by part number — brand doesn't matter as long as it's NGK or Champion.
5. Gaskets (most of them)
Reputable aftermarket gasket sets from Stens, Rotary, and similar brands match OEM dimensions and material specs. The OEM markup on a $4 valve cover gasket is hard to justify.
6. Carburetors on carbureted equipment
Modern aftermarket carburetors from reputable suppliers have closed most of the quality gap with OEM, especially for the most popular Honda GX-series and Briggs-Stratton applications. A $40 aftermarket carb for a GX160 will perform identically to a $120 Honda carb in 95% of cases.
Exception: for high-altitude work or unusual conditions, OEM is more likely to be properly tuned out of the box.
7. Recoil starter assemblies
The mechanical complexity of a recoil starter is low. Aftermarket recoils for Honda GX, Briggs commercial, and similar engines are usually a smart buy at half the OEM price.
Where aftermarket is dangerous
1. Anything pressure-bearing
Hydraulic hoses, fittings, pressure vessels. If the failure mode is "explosive rupture under pressure," buy the part with the engineering documentation behind it.
2. Electrical safety components
Voltage regulators, AVRs on generators, circuit breakers. The cheap aftermarket versions cause fires.
3. Sealed bearings in critical applications
Eccentric bearings on plate compactors, spindle bearings on power trowels. The OEM bearings are usually SKF, NSK, or Timken — buy those (or premium-grade aftermarket equivalents) directly. Skip the no-name boxes.
4. Tires
For towable mixers and pressure washer trailers, buy load-rated tires from a real tire manufacturer. Trailer tires from random no-name brands fail spectacularly.
How T&L sells parts
Every product listing on shop.tandlequipment.net notes:
- The OEM equivalent part number (always, if applicable)
- Whether the part we're selling is genuine OEM or tested aftermarket
- Cross-references and superseded part numbers
You decide which one you want. We stock both. We don't hide the aftermarket parts from you, and we don't push OEM markup when aftermarket performs identically.
The bottom line
For most service items on common equipment, mid-grade aftermarket from a reputable supplier is the right call — same performance, 30-50% less cost. For internal engine parts, safety-critical components, and pressure-bearing parts, pay for OEM.
If you're not sure for a specific part, call us at (702) 798-4149 and ask. We'll tell you straight.
Browse our parts catalog — over 13,600 parts in stock at our North Las Vegas warehouse.
— T&L Equipment, the Southwest's most honest construction-equipment parts source. We sell both OEM and aftermarket, and we tell you which one to actually buy.