Is Expensive Coolant Worth It?

Scientific concepts, discoveries, and phenomena

Cooling / heat-transfer principles

• Heat transfer goal: Antifreeze/coolant must absorb heat from engine metal and transfer it through pipes to the radiator so the heat can be dissipated to the atmosphere.

• Thermal conductivity (rate of heat conduction):

  • Higher thermal conductivity generally improves heat transfer.
  • Water is cited as exceptionally high: ~0.6 W/m·K at room temperature.
  • Ethylene glycol: ~0.258 W/m·K.
  • Propylene glycol: ~0.147 W/m·K.

• Specific heat capacity (heat storage before temperature rises):

  • Water can absorb lots of heat with less temperature rise (framed as a key advantage in the video).

• Freezing and boiling points as practical limits:

  • Water’s freezing point (~0°C) and boiling point (~within engine operating range) make it unreliable without additives.
  • Boiling coolant is harmful because it creates vapor bubbles and a vapor layer between metal and liquid, drastically reducing heat transfer, causing engine temperature to surge.

Chemical properties of antifreeze types

• Ethylene glycol (EG):

  • Boiling point: ~197°C
  • Freezing point: ~−12°C
  • Less thermally conductive than water.
  • More toxic than propylene glycol (toxicity is repeatedly referenced).

• Propylene glycol (PG):

  • Boiling point: ~187°C
  • Freezing point: ~−59°C
  • Even lower thermal conductivity than EG (per the cited values).
  • Framed as less toxic.

• Typical coolant mixtures:

  • Often water + ethylene glycol (commonly ~50/50) to balance:
    • good heat transfer from water
    • higher boiling protection from glycol
  • Additive packages are included (corrosion protection, anti-foaming).
  • Additives and glycol chemistry degrade, giving most products a limited service life.

Product-specific claims tested / discussed

• Evans (anhydrous inhibitor package; mostly ethylene glycol):

  • Designed for full service life without the typical “running out” inhibitor package.
  • Discussion claim/assumption: because it’s mostly EG (and nearly no water), it has:
    • higher boiling resistance
    • lower thermal conductivity than water-rich mixes

• Engine Ice (water + propylene glycol mixture):

  • Designed to provide freeze/boil protection while using less toxic PG.
  • Video highlights that product ratios vary (different offerings for different powertrain segments), affecting freezing/boiling behavior and heat capacity.

Key experimental methodology (stress test for boiling behavior)

The video describes a repeatable, overheating-focused test:

• Goal: Compare when each coolant boils and how overheating behavior appears in the engine.

• Instrumentation / measurements:

  • Radiator temperature used as a proxy for coolant temperature.
  • Exhaust temperature measured near the head (same location each time) as a proxy for what’s happening in the engine.
  • Temperature readings recorded every minute.

• Procedure:

  • Start with one motorcycle; test all products in one day.
  • Step 1: Run on regular coolant until boiling to establish initial warm conditions.
  • Step 2: Drain the coolant, refill with:
    • water
    • Engine Ice
    • Evans
  • Step 3: Rev slightly at idle (carbureted motorcycle) and wait for boiling.
  • Stop criteria: Once boiling becomes very violent (to avoid engine damage and because further data becomes less meaningful).

• Observed results (as presented):

  • Radiator temperature: All coolants except Evans boiled around the 4th–5th minute; test stopped there for those.
  • Exhaust temperature:
    • With water/regular coolant, exhaust temperature rises quickly then flattens as warming proceeds; exhaust keeps rising even as coolant begins to boil.
    • Engine Ice anomaly: violent boiling/spraying near the boiling point caused measurement instability and made the data unreliable.
    • Evans anomaly: exhaust temperature drops from about the 5th to 6th minute, while Evans remained liquid longer.

• Interpretation offered:

  • Evans “stays liquid longer” and continues protecting after others boil over.
  • Not framed as a thermostat-like control at normal operating temperatures—this is described as a stress test at abnormally high temperatures.

Myth-busting and nuanced conclusions

• Myth addressed: “Boiling antifreeze cools the engine fastest because it absorbs a lot of heat.”

  • The video argues there is a small truth (latent heat/heat absorption), but the conclusion is wrong because once boiling forms a vapor layer, heat transfer collapses, leading to worse cooling.

• Thermal conductivity vs real-world outcome:

  • Despite water’s higher thermal conductivity, the test suggests the dominant difference among these products (in this setup) is primarily boiling point / remaining-liquid time, not just thermal conductivity.

• Marketing skepticism (Engine Ice):

  • Mentions a claim of “higher temperature drop” supposedly independently lab tested, but the speaker cannot find the report or understand comparison details.

• Additive precipitation (Engine Ice):

  • Observed sediment/precipitate, requiring shaking before pouring to ensure additives reach the system.

• Freezing protection depends on mixture:

  • Trade-offs emphasized:
    • Pure ethylene glycol alone isn’t as good as mixtures.
    • Mixing EG with water improves freezing performance (50/50 gives a better freezing point than either alone).
    • Evans is described as reaching about −40°C without water (verified by the speaker via Canadian winter experience).

• Emergency dilution with Evans (roadside claim addressed):

  • If low on coolant, water can be added to Evans.
  • Downside: boil-off protection drops toward that of regular antifreeze.
  • Upside: because boiling is less likely, fluid loss risk is reduced.

Other overheating mitigation options compared

• Higher-pressure radiator cap:

  • Raises coolant boiling point by increasing system pressure.
  • Trade-off: higher pressure can stress gaskets and hoses.

• Radiator fan:

  • Framed as most effective for heat removal because it improves airflow through radiators.
  • Limitation: depends on electrical system; fans can draw enough power to cause issues (stalling, stator/battery limits).

• Fan vs “higher boiling point”:

  • Increasing boiling point mainly helps stay liquid longer, but does not necessarily increase instantaneous heat-transfer efficiency.

• Other indicators of overheating (not coolant as a sensor):

  • Detonation, unstable idle, smells (e.g., transmission oil), etc.
  • Steam is one sign, but not the only one.

• High-performance impeller:

  • Could help if there are rare coolant circulation problems.

• Core principle summarized:

  • Overheating happens when engine heat generation > cooling system heat removal capacity.
  • When coolant boils, engine temperature rises rapidly.

Lists / methodology (bullet outline)

• Experimental design

  • Use one motorcycle, test products sequentially in one day.
  • Measure:
    • radiator temperature (coolant temperature proxy)
    • exhaust temperature near the head (engine-condition proxy)
  • Record temperatures every minute.
  • Warm engine using regular coolant until boiling to standardize starting conditions.
  • Replace coolant with test fluid (water, Engine Ice, Evans) and drive to boiling/stress point.
  • Stop tests when boiling becomes violent enough to invalidate readings or risk engine damage.

• Comparative targets

  • When each coolant begins to boil.
  • How exhaust temperature responds during/after boiling onset.

Researchers / sources featured

• No specific individual researchers or external named sources are cited in the provided subtitles.