Introduction
Alternator failure can occur due to various mechanical and electrical problems. Worn-out bearings and electrical overloads are common causes. In such circumstances, replacing an alternator is a necessity instead of a choice. The main issue is choosing between real OEM alternators and cheaper aftermarket options.
It isn’t just about cost—it’s reliability versus affordability.
Aftermarket alternators look like a cheap option, but they can have hidden costs and risks.
Most users end up asking: Should you choose OEM reliability or the cost-effectiveness of aftermarket? Would it be worth saving some bucks to choose aftermarket Alternators?
Dive into the facts to make an informed decision that protects your vehicle and your wallet.
Possible problems with installing a cheap alternator
1. Fail to Meet Power Demands
Some budget aftermarket alternators cannot produce their advertised output. These alternators often fail when users run high-power features. This includes using headlights, air conditioning, and premium audio systems at the same time.
The vehicle draws power from the battery whenever its electrical needs exceed what the alternator can generate. The battery subsides its power charge at an unexpected rate. This happens because the alternator doesn’t provide enough power to recharge it fully.
Regular partial recharging damages the battery’s chemistry, reducing its charging capacity. As a result, the battery can fail early, leading to surprise replacement costs.
2. Reduced Operational Lifespan
Budget alternators are notorious for failing far sooner than OEM or premium aftermarket models. Subpar materials like brittle plastic housings, low-grade copper windings, or weak bearings degrade quickly under daily stress.
For instance, inferior bearings may seize within months, causing the serpentine belt to snap and strand the vehicle. Cheap replacement alternators may only last 1–2 years. In contrast, OEM alternators typically last 7–10 years. This means you could face repeated replacements and higher labor costs.
3. Increased Fuel Consumption
Inefficient rectifier bridges and outdated diode designs create higher mechanical drag.
Cheap units often miss advanced designs, like overrunning clutches or lightweight rotors. This makes the engine work harder to spin the alternator pulley, forcing engines to work 1.5–2% harder. This increases fuel use by 0.3–0.5 MPG in city driving. Over 15,000 miles, this wastes 30–50 gallons of gasoline.
4. Excessive Operational Noise
Low-quality alternators are often louder than OEM models due to poor component tolerances. Common issues include:
- Bearing whine: 85–95 dB at 2,000 RPM (vs. OEM’s 75 dB).
- Belt chirp: Caused by pulley misalignment in 23% of installations.
- Electromagnetic whine: Loose stator lamination generates high-frequency noise.
- Rhythmic clicking: A loose diode trio.
5. Limited Warranty Coverage
Only 15% of budget alternators offer warranties beyond 90 days, compared to 3–5 years for OEM parts. Most exclude coverage for:
- Voltage regulator failures (28% of reported issues)
- Bearing noise complaints
- Heat damage from sustained high loads
If the alternator fails prematurely, you’ll pay out-of-pocket for parts and labor. Worse, some manufacturers may reject warranty claims for unrelated engine issues if a non-certified alternator is installed, citing improper modifications.
Advantages of OEM alternators
1. Guaranteed Compatibility and Reliability
OEM alternators are designed to meet the exact specifications of your vehicle’s manufacturer. It ensures seamless integration with the car’s electrical and mechanical systems. This precise fit removes risks from aftermarket parts.
There won’t be issues like improper alignment or uneven performance. Because these alternators are built to match the original design. With reliable performance, they reduce premature failures or damage to other components in the vehicle.
2. Superior Quality and Longevity
OEM alternators use high-quality materials. These include diodes, stators, bearings, rotors, and voltage regulators. They also rely on advanced engineering processes. This results in enhanced durability and a longer lifespan compared to many aftermarket options.
For example, features like brushless designs in some OEM models reduce wear and tear. These alternators also come with smart suspension systems and gel-packed electrical connectors that protect against vibrations, bumps, and harsh conditions. All these things ensure consistent performance over time.
The longer lifespan results in fewer replacements and reduced maintenance costs. Thus, it saves you money in the long run.
3. Warranty Protection and Peace of Mind
A genuine OEM alternator protects your vehicle’s warranty terms. A manufacturer will typically void your warranty when you repair your vehicle with aftermarket components.
OEM alternators typically receive a strong warranty coverage of between 12 and 24 months. The warranty includes protection for defects during a predefined time frame. The warranty coverage guarantees both investment protection and worry-free repair options for the future.
Get OEM alternators at Unitechmotor
Unitechmotor focuses on manufacturing premium OEM alternators that support many different vehicle brands, including Bosch, Denso, Mitsubishi, and Valeo. We offer comprehensive solutions by uniting product design aspects and manufacturing and distribution services under one platform. The best part is the factory-direct pricing. Plus, our strict quality testing makes them a reliable choice for durable and affordable automotive parts. Shop your alternator now!