Red Line Fluid Recommendations for Honda Civic Type R (K20C1)
Red Line Fluid Recommendations for Honda Civic Type R (K20C1)
Engine Oil
The engine requires 5.4 litres (5.7 quarts) when changed with the oil filter
Red Line 5W-30
For high performance street use.
Red Line 0W-20 Synthetic Racing Oil
Track use only
Optimized for modern turbocharged engines, this full-ester blend maintains film thickness at high RPM and resists shear under boost.
• Oil Change Interval
8,000–12,000 km under spirited driving or track use; 12,000 – 15,000 km for street only.
• Why Red Line?
Superior ester base resists heat-soak, minimizes oxidation, and cushions high-frequency shock loading.
• Independent Feedback
“RedLine 0W-20 has been rock-solid in my 1.5T-powered Civic Touring—no consumption and rock-hard oil pressure.” (use this oil for track use only)
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Gearbox (Manual Transmission)
Red Line MTL™ Synthetic Gear Oil 75W-80 for everyday use
The manual gearbox requires 1.8 litres (1.9 quarts)
Includes Torsen LSD; same fluid serves transmission and differential
GL-4 formula engineered for synchro protection, delivering crisp, predictable shifts.
• Warm the fluid to ~40 °C before filling for accurate level.
• Fill to the bottom of the filler port to ensure full lubrication under hard launch.
Red Line MT 85 and MT 90 synthetic gear oil for track use and spirited outings.
• User Impressions
“MTL feels more precise than OEM MTF—zero gearbox rattle after 20,000 km.”
• Feedback
“With Red Line plus friction modifier, my Torsen-type LSD stopped chattering even on cold mornings.”
Additional Recommendations
• Install a high-flow 10-micron oil filter to trap micro-wear particles and extend engine life.
• Fit an oil-temperature gauge to keep temps below 120 °C during track use.
• Consider a catch can or upgraded crankcase breather to reduce intake coking in high-boost scenarios.
Why Red Line Over OEM and Other Synthetics?
- Ester Chemistry – Polar esters bond strongly to metal, creating a tenacious film even under momentary boundary-lubrication regimes seen in synchro and spur-gear teeth.
- Thermal & Oxidative Stability – Red Line’s oils resist viscosity breakdown, permitting longer service intervals and more consistent protection.
- Friction & Wear Control – Proprietary additive package (detergents, anti-wear agents, friction modifiers) balances shift feel, reduces gear and bearing wear, and keeps internal parts cleaner.
- Race-Proven Performance – You can rely on Red Line’s gearbox and motor oils to extract maximum horsepower while safeguarding components.
- Seals and Gasket Compatibility – Formulated to be seal-friendly, minimizing leaks and eliminating harsh chemical interactions common with some aftermarket synthetics.
Switching your Honda to the recommended oils leverages Red Line’s advanced ester-based lubricants for maximum performance, longevity, and driving enjoyment.
Other Considerations & Next Steps
- Always confirm fluid levels and torque the fill/drain plugs per factory service manual.
- Consider Red Line’s high-temperature brake and clutch fluid (Dot 5.1) if you track your Honda; it pairs seamlessly with esters for a fully integrated high-performance service plan.
- Keep a maintenance log of dates, mileages, and fluid change brands to track wear trends and optimize service intervals.
Protect Your Engine
Keep the fuel flowing at optimum levels by making sure the injectors remain unclogged.
Red Line SI-1 Fuel System Cleaner
Cleans injectors, carburetors, valve and combustion chamber deposits with a concentrated blend of the most powerful high-temp and low-temp detergents available
- Cleans all forms of fuel injectors, including GDI
- Enhances fuel stability; reduces gum and varnish formation
- Use one bottle per tank for most effective treatment, cleans to nearly 100% efficiency in one treatment
- On a GM 3.8 litre V6 engine the 0 to 70 KPH was increased by 21% after unequally plugged injectors were cleaned with SI-1 injector cleaner.
Keep Your Cool.
Use Red Line Water Wetter in the Radiator
One bottle of Red Line Water Wetter in the radiator will decrease the cylinder head temperature by 10 degrees C.
This reduction in temperature may allow more spark advance to increase torque.
All this while reducing rust and corrosion and cleaning and protecting water pump seals.
If your vehicle is air conditioned the cooling system requires anti-freeze use Red Line Supercool fortified with Water Wetter.
Red Line Brake Fluid Options
Red Line offers high-performance brake fluids that exceed factory DOT 4 specifications, making them a popular upgrade for the FK2/FK8 Civic Type R’s K20C1 powertrain. Their formulations focus on high dry- and wet-boiling points, low compressibility, and stable viscosity to deliver crisp pedal feel and fade resistance under spirited driving or track use.
Why It Suits the K20C1 Civic Type R
• The stock brake system on the FK2/FK8 expects DOT 4; upgrading to RL-600 raises both dry- and wet-boiling points by over 50 °C.
• Enhanced fade resistance keeps the twin-piston front and single-piston rear calipers from softening under repeated heavy stops—ideal for canyon runs or fast road courses.
• Ester-based chemistry resists vapor lock maintains viscosity across a wide temperature band (critical in both cold-region morning commutes and hot braking events) and preserves ABS pump response.
• No special seal or ABS-module refresh is needed when switching from OEM DOT 4 to RL-600 or RL-700.
Community Feedback & Independent Impressions
• Owners on Civic forums repeatedly praise RL-600 for delivering a “factory-plus” pedal feel—sharper bite without the harshness some racing fluids exhibit.
• Track-day enthusiasts note that RL-700 trades a bit of cold-weather responsiveness for near-total fade immunity in multi-session events.
• A handful of DIY reviews emphasize the importance of a fresh fluid change every 12–18 months (or sooner if the car sees regular track days) to preserve peak boiling characteristics.
Recommendations & Next Steps
1. For primarily street-driven Type Rs with occasional spirited outings, RL-600 DOT 4 offers the best balance of cold-weather responsiveness and heat resistance.
2. If you plan full-day track events or back-to-back lap sessions, step up to RL-700 Racing fluid.
3. Always follow a proper flush and bleed procedure—consider a pressure-bleeder and a desiccant-style reservoir cap to minimize moisture ingress.
4. Monitor pedal feel and brake temperatures in your first few drives; switching to a high-boiling fluid can subtly change pedal firmness and ABS modulation thresholds.