TEC 2000 vs K2 Engine Flush: which one should you choose?
Short answer: both are solvent-based engine flushes (oil-system flushes) built on aromatic solvents, and neither one is a “kerosene” product, whatever you may have read. The difference sits elsewhere. K2 Motor Flush is a cheap, single-ingredient solvent flush - around 11 PLN (about €2.50) per 250 ml - based on a reaction mass of ethylbenzene and xylene, and its safety data sheet declares no lubricating additive. TEC 2000 Engine Flush costs several times more per millilitre. Per its safety data sheet it runs on an aromatic solvent base, chlorine-free and kerosene-free, with an additive package that carries two anti-wear agents: a sulphurised olefin and ZDDP (CAS 6990-43-8). The maker declares it seal-safe. Is bare price the only thing that counts? K2 is cheaper. The difference between them is not whether the engine is healthy, though; it is whether the sheet lists a buffer. K2 lists no protective additive at all, TEC 2000 lists ZDDP and a sulphurised olefin. Want a flush that skips the miracle claims, on a brand that has been around for decades? Then it is TEC 2000.
The rest of this guide gets into the detail: what the safety data sheets actually list, how each one behaves in the sump, how you dose and time them, and whether the price gap buys you anything.
Who this guide is for
You are about to change your oil, you want to flush the system first, and you are stuck between the cheap K2 everyone knows and the pricier TEC 2000. That is the spot this guide is written for. We ignore the label promises and go by what the safety data sheets list, how each product works on the deposits, and whether TEC 2000’s higher price pays for itself. Not sure you even need a flush? Start with which engine flush is the best.
The key differences at a glance
Both work the same way. You pour an aromatic solvent into hot oil just before you drain it. Where they part company is what else is in the bottle, and what you pay for it.
- Chemical base. K2 is a reaction mass of ethylbenzene and xylene (up to 70%, EC no. 905-562-9). TEC 2000 is a hydrocarbon solvent blend on an aromatic base, plus an additive package, chlorine-free and kerosene-free. Both sit on aromatics. Neither is kerosene.
- Anti-wear additive. K2’s safety data sheet lists a solvent and nothing else, so there is no lubrication in the bottle. TEC 2000’s lists two: a sulphurised olefin and ZDDP (CAS 6990-43-8), both inside its additive package. The ZDDP is the same anti-wear chemistry a premium rival like Liqui Moly declares on its own card, and TEC 2000 carries the sulphurised olefin alongside it. That is the real split. One bottle is bare solvent. The other holds on to the oil film while the engine idles.
- Price per millilitre. K2 is far cheaper. TEC 2000 runs several times more for the same volume.
- What each maker promises. K2’s marketing throws in “increased power” and “raised compression”, which no independent research backs. TEC 2000 stays with cleaning and protection and leaves the miracles out.
Composition and safety - what the data sheets say
Composition is what decides how hard a product bites at deposits and seals, so this is the part worth reading slowly. Everything below comes from the official safety data sheets (SDS), not shop copy.
K2 Motor Flush (T371)
The current sheet - version 4, dated 12 May 2021, from Melle Sp. z o.o. - lists one hazardous component: a reaction mass of ethylbenzene and xylene at below 70% (EC no. 905-562-9). It is an aromatic solvent. It cuts sludge and varnish well, and it lubricates nothing.
On the CLP label it carries the signal word “Danger” Nothing unusual there. That is the normal hazard profile for a solvent flush.
One correction worth making: people online keep mixing up K2 Motor Flush with the older, discontinued K2 Turbo Motor Flush, which really did run on heavy naphtha (kerosene-range petroleum, CAS 64742-82-1). The current K2 Motor Flush T371 is not a kerosene product. It is built on xylene and ethylbenzene. So when you read that “K2 is kerosene”, that is the old product talking, not this one.
TEC 2000 Engine Flush
Per its safety data sheet, TEC 2000 Engine Flush runs on an aromatic solvent base with an additive package, chlorine-free and kerosene-free, which is also what keeps it safe on Nikasil coatings. The same sheet lists two anti-wear agents in that package: a sulphurised olefin and ZDDP (CAS 6990-43-8). So the oil-film protection is not a marketing line. It is in the card, in black and white. TEC 2000 also declares its formula safe for rubber seals, and it was one of the first flushes to drop chlorinated hydrocarbons altogether. The full component breakdown, ours and the rivals’, sits in one place - see our engine flush safety data sheets.
Why a lubricating additive in a flush matters
The lubrication side is simple physics. A pure solvent thins the oil and weakens the film, and even at idle a thinned film is a bad moment for the bearings and the cam lobes. A flush that brings its own anti-wear additives holds on to some of that protection through the ten-odd minutes the engine runs dirty. That is the job of the sulphurised olefin and the ZDDP in TEC 2000’s additive package, and both are on the safety data sheet, not just the tin. K2 has nothing of the sort. Once its solvent goes in, the oil is on its own.
Oil-flush comparison table
The table puts TEC 2000 next to the other popular oil flushes. Figures come from safety data sheets and maker materials; anything still marked “to verify” is being filled in as we get the sheets.
| Brand | Product | Base / strength | Lubricant buffer (SDS) | Kerosene | Key feature | Verdict |
|---|---|---|---|---|---|---|
| LIQUI MOLY | Pro-Line Engine Flush | Mixed · Strong | ZDDP 1-2.5%, no EP additive | No - hydrocarbons C10-C13, under 2% aromatics (70-90%) + paraffinic fractions | Dearomatised C10-C13 base with ZDDP at 1-2.5% and calcium sulfonate at 1-2.5% (Section 3). The regular Engine Flush 2640 has the same declared composition as Pro-Line | Effective premium solvent; the sheet lists ZDDP protecting surfaces during the flush |
| Wynn's | Motor Cleaner - Oil System Cleaner 325 ml | Mixed · Medium | None in the SDS | Heavy petroleum distillates (≥50%) + C10 aromatic hydrocarbons 10-15% | Kerosene base with C10 aromatics and amine; notably higher aromatic content than premium brands | Strong dissolving action from aromatics, but kerosene base with diethanolamine raises questions about compatibility with modern seals |
| Bardahl | Engine Flush / Pre-Drain Cleaner 300 ml | Kerosene/heavy · Strong | None in the SDS | Hydrocarbons C10-C13 (80-95%) + kerosene 1-10% | C10-C13 solvent dominant; kerosene addition boosts dissolving power, no lubricant additive | Solid solvent formula with kerosene addition; absence of lubricant means no seal protection during the flush cycle |
| MANNOL | Motor Flush 9900 | Mixed · Medium | Calcium sulfonate (detergent), no ZDDP | Mineral oil base; only disclosed hazardous ingredient is ethoxylated isotridecanol (<0.5%) | Very sparse SDS - mineral oil base with calcium sulfonate, limited composition data | Budget option with limited SDS data; difficult to assess full composition without complete safety sheet |
| Moje Auto | MA Professional Engine Flush 400 ml | Heavy synthetic (GTL) · Gentle | None in the SDS | No - synthetic GTL Fischer-Tropsch base (heavy distillates C18-C50) 75-85% | The only declared component is a GTL synthetic (Fischer-Tropsch, CAS 848301-69-9) at 75-85%; the sheet lists no lubricant additive or detergent and does not declare the remainder | Budget flush on a heavy C18-C50 synthetic base, gentle on seals (the sheet lists H304 only). A heavy fraction dissolves less than light solvents, and the sheet declares no lubricant additive |
| TEC 2000 ⭐ BEST PICK | Engine Flush | Aromatic · Very strong | ZDDP + sulphurised olefin (EP) | No | Advanced hydrocarbon solvent blend (aromatic base) + additive package with ZDDP (anti-wear, CAS 6990-43-8, listed in SDS v3.1); chlorine-free, no kerosene | Top pick - effective and seal-safe |
| Motul | Engine Clean Auto | Aromatic · Medium | None in the SDS | Hydrocarbons C10-C13, <2% aromatics (50-100%) + light paraffinic distillate (10-25%) | Pure C10-C13 solvent base; no ZDDP or other lubricant additives | Proven solvent from a premium brand, but purely solvent-based - TEC 2000 additionally offers a lubricant component protecting seals |
| K2 | Motor Flush T371 250 ml | Aromatic · Very strong | None in the SDS | Reaction mass of ethylbenzene and xylenes (<70%); aromatic hydrocarbons | Aromatic base (ethylbenzene + xylenes) - powerful solvent, classified as flammable and harmful by inhalation | High-activity aromatic formula effectively removes deposits, but xylenes carry higher OHS risk than the light C10-C13 alkanes used by premium competitors |
| Mathy | MATHY-C Motor Interior Cleaner (Engine Flush) 400 ml | Mixed · Medium | ZDDP 1-3%, no EP additive | Hydrocarbons C12-C15, <2% aromatics (50-100%) + sodium petroleum sulfonate (5-10%) | Unique 3-component formula: C12-C15 solvent + sulfonate detergent + ZDDP (1-3%) | One of the few competitors with a ZDDP component; similar approach to TEC 2000 (solvent + lubricant balance), though with a different type of lubricant additive |
| STP | Engine Flush 30-011 450 ml | Mixed · Strong | ZDDP 1-3%, no EP additive | Hydrocarbons C11-C14, <2% aromatics (50-100%) + heavy paraffinic distillate (10-25%) | C11-C14 solvent with paraffinic base oil and ZDDP (1-3%) - three component classes | Competent formula with ZDDP providing anti-wear protection; similar philosophy to TEC 2000, but solvent base dominates |
| Castrol | Engine Shampoo (Castrol Flush) 300 ml | Light aliphatic · Gentle | Molybdenum dithiocarbamate (friction modifier) | Hydrotreated heavy paraffinic distillate (≥75-90%); light solvents as minor fractions (≤3%) | Exceptionally oil-heavy base (≥75% heavy distillate) + trace molybdenum dithiocarbamate friction modifier | Gentle paraffinic oil-based formula - minimal seal risk, but limited dissolving power; TEC 2000 achieves solvent+lubricant balance without such a dominant oil base |
| Comma | Engine Flush (Petrol/Diesel) 400 ml | Mixed · Medium | ZDDP under 1%, no EP additive | Hydrotreated heavy paraffinic distillate (15-25%) as main disclosed ingredient; full composition not revealed in SDS | Limited SDS data; declared ZDDP (<1%) and alkyl phenol (<1%) as additives | Insufficient SDS data makes full assessment difficult; ZDDP presence is positive, but low concentration and lack of composition transparency |
| Forté | New Generation Motor Flush 400 ml | Aromatic · Strong | None in the SDS | Hydrocarbons C10-C13 with aromatics 2-25% (≥50%) + C10 aromatics (10-25%) + glycol ether DPM (10-25%) | 3-solvent formula with notable C10 aromatic and DPM glycol ether content; no lubricant additive | Aggressive solvent formula (aromatics + glycol) effectively breaks down varnish and sludge; no lubricant component - seals unprotected during flush |
Comparison data is being expanded and verified from manufacturer sources.
How to use it - step by step
You use both the same way, and it is hard to get wrong. These go into the old oil right before you drain it. They are not fuel additives you tip in the tank. For the long version, see our guide to a petrol engine flush done correctly.
- Warm the engine to operating temperature, then leave it idling.
- Pour in the flush through the oil filler. K2: one 250 ml bottle per roughly 4-6 L of oil. TEC 2000: per the manufacturer, one dose per 4-5 L of oil.
- Leave it idling - K2 states 10-15 minutes, TEC 2000 about the same (longer for a badly neglected engine). Do not drive with the flush in the oil, and do not load the engine.
- Drain the old oil together with the flush, replace the oil filter, and refill with fresh oil.
Two things not to do: don’t leave the flush in and go for a drive to “let it work”, and don’t put it in a two-stroke. If the engine is high-mileage and caked up, read what to watch for when flushing a high-mileage engine before you start.
Price and value
This is the gap you can actually put a number on. K2 Motor Flush costs around 11 PLN (about €2.50) per 250 ml. TEC 2000 Engine Flush sits at the premium end - per millilitre it lands somewhere around three to four times the price of K2.
Is it worth it? Depends what you are buying. With K2 you are paying for the solvent, and the solvent will shift deposits. With TEC 2000 you are paying for a cleaner, chlorine-free solvent base, a two-agent anti-wear package that guards the oil film during the flush, and a brand that has been on the shelf for decades. Flushing a healthy engine once before you sell the car? K2 is plenty. An engine you plan to keep, or one you service on a schedule? The extra you pay for TEC 2000 buys margin.
What no flush will do
A few myths need putting down, marketing copy included. No flush “removes every deposit in 10 minutes”, and none “reverses” engine wear. The hard, coked-on stuff is bonded to the metal, and no detergent dissolves it; the best a flush does is loosen it and hold it in suspension so it leaves with the drain. The oil and the flush carry the muck out. They do not scrub the engine on their own.
So K2’s louder claims - “increased power”, “raised compression” after a 10-minute flush of the oil system - are promises with no independent research behind them. How deposits form and how oil oxidises is well documented (see Machinery Lubrication on the stages of oil oxidation and the field study of oil degradation in Energies, 2023), and none of it leaves room for a compression miracle out of a bottle of additive.
Verdict: K2 or TEC 2000?
Go with K2 Motor Flush if you want the cheapest, simplest way to flush a healthy engine once before an oil change, and you are not fussed about extra protection or a brand name.
Go with TEC 2000 Engine Flush if you want the cleaner, chlorine-free solvent base with a two-agent anti-wear package - a sulphurised olefin and ZDDP - for oil-film protection, a formula declared safe for seals, and a maker that does not dangle power or compression gains in front of you. It costs more. On paper it is the one that adds up.
Both flushes are solvent-based and kerosene-free. What separates them is what rides in with the solvent - bare solvent for K2, a chlorine-free base plus an anti-wear package for TEC 2000 - and how straight each maker is about what the stuff can do. It was never about “kerosene content”, whatever gets pinned on one side or the other. For the same matchup against another premium rival, see our TEC 2000 vs Liqui Moly comparison; for the full teardown of nine brands’ compositions, read engine flush ingredients exposed.
FAQ
Does K2 Motor Flush contain kerosene?
No. The current K2 Motor Flush (T371) runs on a reaction mass of ethylbenzene and xylene (EC no. 905-562-9), not kerosene. The older, discontinued K2 Turbo Motor Flush did use heavy naphtha, but that is a different product.
How long should you leave a flush in the engine?
Both brands say much the same: about 10-15 minutes at idle. Don’t drive it and don’t load it during that time. Then drain the oil with the flush still in it and change the filter.
Is engine flush safe for seals?
TEC 2000 declares its formula safe for rubber seals. K2 is a solvent flush and is fine used as instructed - briefly, before an oil change - as long as you don’t overrun the time or drive on it. On a high-mileage engine with seals you already suspect, go easy with any aggressive flush.
Which is better - K2 or TEC 2000?
For a one-off on a healthy engine, the cheaper K2 is enough. Want the extra oil-film protection and a maker that doesn’t oversell? TEC 2000 is the better pick. Neither one “repairs” an engine or reverses wear.
How much flush should you add?
K2: one 250 ml bottle per roughly 4-6 L of oil. TEC 2000: one dose per 4-5 L of oil, per the manufacturer. Don’t go over the dose.
Author: the plukankasilnika.pl team - specialists in cleaning oil and drivetrain systems. This article is based on manufacturers’ official safety data sheets and independent sources on oil aging and deposit formation. As of 26 June 2026.
Sources
- K2 Motor Flush (T371) Safety Data Sheet, version 4, 12 May 2021 - Melle Sp. z o.o.
- K2 - official product page for K2 Motor Flush 250 ml (k2.com.pl).
- TEC 2000 Engine Flush - official safety data sheet and product materials (tec2000.pl).
- Machinery Lubrication - “Identifying the Stages of Oil Oxidation”.
- Energies 2023, 16(24), 7955 - field study of engine oil degradation (MDPI).
