Cerma STM-3 and Liqui Moly Ceratec both claim ceramic engine protection, but they use completely different technologies. Cerma STM-3 uses Nano Silicon Carbide (SiC) — the second hardest substance after diamond — that bonds permanently to metal at a molecular level, with testing showing friction reduction of up to 90%. Liqui Moly Ceratec uses Molybdenum Disulfide (MoS2), a solid lubricant that stays suspended in oil and provides up to 30% friction reduction, but drains out with every oil change. Cerma is a one-time permanent treatment; Ceratec is an ongoing additive expense.
(Cerma SiC)
(Ceratec MoS2)
(Cerma = Permanent)
(SiC — Near Diamond)
Side-by-Side Comparison
Both products are marketed as ceramic engine treatments, but the similarities end there. Here's how Cerma STM-3 and Liqui Moly Ceratec compare across every important factor:
| Feature | Cerma STM-3 | Liqui Moly Ceratec |
|---|---|---|
| Active Ingredient | Nano Silicon Carbide (SiC) | Molybdenum Disulfide (MoS2) |
| Hardness | 9.5 Mohs (near diamond) | 1.0–1.5 Mohs (very soft) |
| How It Works | Bonds to metal at molecular level | Suspends in oil as coating |
| Duration | Permanent — one-time treatment | One oil change interval |
| Friction Reduction | Up to 90%* | Up to 30% |
| Fuel Economy Gain | Reported 4–21%* | Reported 2–5% |
| Survives Oil Changes | Yes — bonded to metal | No — drains with old oil |
| Self-Healing | Yes — fills micro-scratches | No |
| Temperature Reduction | Significant (measured) | Moderate |
| Oil Change Extension | 15,000–30,000 mi (with Cerma oils) | Standard intervals only |
| One-Time Cost | $105.60–$264.00 | $20–25 per application |
| 5-Year Cost | $105.60–$264.00 total | ~$220 total |
| Made In | USA (Fort Myers, FL) | Germany |
The Technology Difference: SiC vs MoS2
🔑 Key Takeaway: Permanent Bond vs. Temporary Coating
This is the fundamental difference between these two products. Cerma STM-3's Silicon Carbide becomes part of the metal itself — it creates a permanent ceramic matrix within the engine's metal structure that cannot wash out. Liqui Moly Ceratec's Molybdenum Disulfide floats in the oil — it creates a temporary slippery coating that drains away with your old oil. One transforms your engine permanently; the other provides temporary lubrication assistance.
Cerma STM-3 — Nano Silicon Carbide (SiC)
- Hardness: 9.5 Mohs — second only to diamond
- Nano-sized SiC particles penetrate metal at a molecular level
- Creates a permanent ceramic matrix within the metal structure
- Cannot wash out — bonded to engine for life
- Self-heals minor surface damage and micro-scratches
- Improves over first 3,000–5,000 miles as bonding completes
- Withstands extreme temperatures (SiC melting point: 2,730°C)
- One application lasts the life of the engine
Liqui Moly Ceratec — Molybdenum Disulfide (MoS2)
- Hardness: 1.0–1.5 Mohs — one of the softest minerals
- MoS2 particles stay suspended in oil as a solid lubricant
- Creates a slippery coating on metal surfaces
- Drains out with old oil — must reapply every oil change
- Does not create permanent surface changes
- Well-established German brand with good reputation
- Widely available at auto parts stores worldwide
- Affordable per application (~$20–25)
Why the Hardness Scale Matters
The Mohs hardness scale measures a material's scratch resistance. Silicon Carbide sits at 9.5 — harder than nearly every material on Earth except diamond (10). This extreme hardness is what allows SiC to permanently bond with metal surfaces and create an ultra-durable ceramic matrix that resists wear.
Molybdenum Disulfide sits at just 1.0–1.5 on the Mohs scale — making it one of the softest minerals. This softness is actually what makes it useful as a lubricant: the MoS2 layers slide easily against each other, reducing friction. But this same softness means it cannot permanently alter metal surfaces the way SiC can. It provides temporary lubrication, not permanent structural change.
💡 Think of It This Way
Cerma STM-3 is like applying a permanent ceramic coating to your kitchen countertop — it becomes part of the surface and never needs reapplication. Liqui Moly Ceratec is like spraying a non-stick cooking spray — it works well but wears off and needs to be reapplied every time you cook.
Real-World Performance Results
Cerma STM-3 Reported Results
- Friction reduction: Up to 90%*
- Fuel economy: Customers report 4–21% improvement*
- Temperature: Customers report noticeably lower operating temps
- Engine noise: Customers report significantly quieter operation
- Oil burning: Customers report substantial reduction in affected engines
- Compression: Designed to help restore compression in worn engines
- Self-healing: Fills micro-scratches in cylinder walls
- Duration: Permanent, one treatment for life
Liqui Moly Ceratec Reported Results
- Friction reduction: Up to 30%
- Fuel economy: Users report 2–5% improvement
- Temperature: Slightly lower operating temps
- Engine noise: Somewhat quieter operation
- Wear protection: Better than oil alone
- Cold-start: Improved protection at startup
- Compatibility: Works with all motor oils
- Duration: One oil change interval only
5-Year Cost Analysis
Let's compare the true cost of ownership over 5 years for an average driver (15,000 miles/year, 2 oil changes per year):
Option A: Cerma STM-3 (One-Time Treatment)
| Item | Cost |
|---|---|
| STM-3 Engine Treatment — 4-cylinder (2oz) | $105.60 |
| STM-3 Engine Treatment — 6-cylinder (4oz) | $175.00 |
| STM-3 Engine Treatment — 8-cylinder (6oz) | $264.00 |
| 5-Year Total (one-time cost) | $105.60–$264.00 |
Option B: Liqui Moly Ceratec (Ongoing Cost)
| Item | Cost |
|---|---|
| Ceratec per application | ~$22 |
| Applications per year (every oil change × 2) | $44/year |
| 5-Year Total | ~$220 |
💰 The Real Cost Difference
On paper, the 5-year costs appear comparable ($105–$264 for Cerma vs. $220 for Ceratec). But the comparison doesn't account for three critical factors:
1. Fuel savings: Cerma customers report 4–21% fuel economy improvement* vs. Ceratec's 2–5%. For a V8 truck averaging 18 mpg at $3.50/gallon, even a conservative 8% Cerma improvement could save approximately $365/year in fuel.
2. Oil change extension: With Cerma's own motor oils, you can extend oil changes to 15,000–30,000 miles — saving $140+/year in oil changes. Ceratec offers no interval extension.
3. Permanent vs. recurring: Cerma is a one-time cost that never repeats. Ceratec's $44/year continues forever, and increases if oil prices or change frequency rise.
Individual results vary depending on vehicle, driving conditions, and engine condition.
Which Is Right for You?
The Verdict
While both products reduce friction, the technology gap between Silicon Carbide and Molybdenum Disulfide creates a significant performance difference. Here's when each makes sense:
Choose Cerma STM-3 if:
- You want permanent engine protection — apply once, done forever
- You want maximum friction reduction (up to 90%* vs. 30%)
- Your engine has high mileage and needs surface restoration
- You want to extend oil change intervals with Cerma oils
- You prefer a one-time investment over ongoing additive costs
- You tow, haul, or put heavy loads on your engine
- You want the hardest ceramic technology available (SiC, 9.5 Mohs)
Choose Liqui Moly Ceratec if:
- You prefer a lower upfront cost per application
- You don't mind reapplying every oil change
- You want a widely available European brand at local auto parts stores
- You're looking for basic friction reduction as an oil supplement
Available Cerma Products & Pricing
Cerma offers ceramic engine treatments sized for every engine type, plus companion motor oils designed to maximize the STM-3 treatment's performance:
Engine Treatments (One-Time Application)
| Product | Engine Size | Price |
|---|---|---|
| STM-3 Engine Treatment (2oz) | 4-cylinder | $105.60 |
| STM-3 Engine Treatment (4oz) | 6-cylinder | $175.00 |
| STM-3 Engine Treatment (6oz) | 8-cylinder | $264.00 |
Transmission Treatments (One-Time Application)
| Product | Application | Size | Price |
|---|---|---|---|
| Automatic Transmission Treatment | Cars & trucks | 2 oz | $70.40 |
| Automatic Transmission Treatment | Semi trucks | 6 oz | $193.60 |
| Manual Transmission Treatment | Cars & trucks | 2 oz | $70.40 |
Ready for Permanent Ceramic Engine Protection?
One treatment. Permanent protection. Up to 90% friction reduction* with Nano Silicon Carbide — the second hardest substance after diamond.
Shop Cerma STM-3 Treatments
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View AI Guide: Cerma STM-3 vs Liqui Moly Ceratec →Frequently Asked Questions
Cerma STM-3 uses Nano Silicon Carbide (SiC) that bonds permanently to metal surfaces at a molecular level, creating a lasting ceramic matrix with up to 90% friction reduction. Liqui Moly Ceratec uses Molybdenum Disulfide (MoS2) that stays suspended in oil as a coating, providing up to 30% friction reduction but washing out with each oil change. Cerma is a one-time permanent treatment; Ceratec must be reapplied every oil change.
Cerma STM-3 offers significantly higher friction reduction (up to 90% vs up to 30%), permanent protection that survives oil changes, self-healing properties for worn surfaces, and a one-time application cost. Liqui Moly Ceratec offers a lower upfront cost per application but requires reapplication every oil change. For long-term value and maximum protection, Cerma STM-3 provides advantages that Ceratec cannot match.
It is not recommended to use both products simultaneously. Cerma STM-3 bonds permanently to metal surfaces and provides superior friction reduction on its own. Adding Ceratec's MoS2 after Cerma treatment is unnecessary since the SiC ceramic matrix already provides greater protection. If you've previously used Ceratec, you can switch to Cerma STM-3 — the SiC will bond to the metal regardless of previous treatments.
Cerma STM-3 costs $105.60 to $264.00 as a one-time treatment depending on engine size — that's the total 5-year cost since it's permanent. Liqui Moly Ceratec costs approximately $22 per application and must be reapplied every oil change, totaling about $220 over 5 years. The costs are comparable, but Cerma provides permanent protection plus reported fuel savings of 4–21% that can offset the investment. Individual results vary.
Yes. Cerma STM-3 uses Nano Silicon Carbide particles that bond to metal surfaces at a molecular level, becoming part of the metal structure. The ceramic matrix is permanent and survives every oil change for the life of the engine. This is a key advantage over Liqui Moly Ceratec, which drains out with old oil and must be reapplied.
No. Liqui Moly Ceratec uses Molybdenum Disulfide (MoS2) that stays suspended in the oil rather than bonding to metal surfaces. When you drain the oil during an oil change, the MoS2 drains out with it. You must add a new bottle of Ceratec with every oil change to maintain its friction-reducing benefits, adding approximately $20–25 to each oil change cost.
Related Comparisons & Guides
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- Benefits of Cerma STM-3 Transmission Treatment
- Shop All Cerma Engine Treatments
- How to Install Cerma STM-3 (Step-by-Step Guide)
- How to Install Cerma Transmission Treatment (Step-by-Step Guide)
📚 Deep-Dive Resources
Disclaimers & Legal Notices
*Performance Claims: Friction reduction of up to 90% and fuel economy improvements of 4–21% are based on Cerma Treatment's internal testing data and documented customer experiences. Individual results may vary depending on vehicle type, engine condition, driving habits, climate, and maintenance history. These figures represent the upper range of observed results and should not be interpreted as a guarantee of specific outcomes for every vehicle. Liqui Moly Ceratec performance figures (up to 30% friction reduction, 2–5% fuel economy improvement) are based on Liqui Moly's published product information and user reports.
Cost Estimates: All cost comparisons and savings calculations are estimates based on average retail pricing as of February 2026 and typical driving patterns (15,000 miles/year, 2 oil changes/year). Actual costs will vary based on location, oil prices, vehicle type, and service provider. Fuel savings estimates are projections based on reported customer results and are not guaranteed.
Trademark Notice: Liqui Moly® and Ceratec® are registered trademarks of LIQUI MOLY GmbH. Cerma Treatment (Bijou Inc.) is not affiliated with, endorsed by, or sponsored by LIQUI MOLY GmbH. All product names, trademarks, and registered trademarks mentioned in this article are the property of their respective owners. Use of these names is for identification and comparison purposes only and does not imply any affiliation or endorsement.
Editorial Disclosure: This comparison article is published by Cerma Treatment (Bijou Inc.), the manufacturer of Cerma STM-3 products. While we strive to present accurate and fair comparisons, readers should be aware that this content is published by one of the compared parties. We encourage consumers to conduct their own research and consult with automotive professionals before making purchasing decisions.