Tyre Pressure Calculator — RE71RS

Honda EK/EM Civic Coupe

FWD · 1100 kg · 62/38 F/R · RHD · 225/50R15 front · 205/50R15 rear · Bridgestone RE71

Cold Pressure Calculation

Session Conditions

Ambient / tyre set temp 20°C

Track surface temp 35°C

Session type

Circuit direction

🌧 Wet conditions

Enable wet mode

In wet conditions tyre surface temperatures do not build through friction — water acts as a coolant and suppresses the plateau. Set cold pressures at or very close to your hot target pressure. Cold set = hot target.

Gas law: P_cold = P_hot × (T_amb_K ÷ T_plateau_K) · Track temp affects the tyre's thermal equilibrium — a 10°C rise in track temp raises plateau ~3–5°C and requires a lower cold set. Both ambient and track temperature changes produce ~0.1 psi per °C effect on hot pressure (Samir Abid / Your Data Driven). Track temp is captured implicitly in your measured plateau temperatures.

Hot Pressure Targets (psi) · Slider range 24–36 psi

Track & ambient temperature correction calculator

Use this when returning to a circuit in different conditions, or between sessions on the same day as ambient and track temperatures change. Rule of thumb: ±0.1 psi per °C change in ambient and ±0.1 psi per °C change in track temperature (Samir Abid / YDD; Jeff Braun / IMSA: 1 psi per 10°F ≈ 0.18 psi per °C). Both act on the tyre's thermal boundary — the gas law approach (using updated plateau temps) is more accurate but requires measured data. This calculator provides a quick session-to-session cold pressure offset.

Reference session (previous data)

Reference ambient temp 20°C

Reference track temp 35°C

FL cold (psi)

FR cold (psi)

RL cold (psi)

RR cold (psi)

Current session — corrected cold pressures

Ambient change—

Track temp change—

Total correction per tyre—

Corrected cold pressures (rule of thumb method)

—

psi

—

psi

—

psi

—

psi

Session temperature log

#	Ambient	Track	Session	FL cold	FR cold	RL cold	RR cold	Notes

Target Tyre Temperature per Corner (°C) · Pyrometer surface reading at plateau

Cold <54°C■ Optimal 54–65°COverheating >65°C

Enter the surface pyrometer temperature you expect (or measured last session) for each corner at plateau. These feed directly into the cold pressure calculation. The RE71RS Super 200 optimal window is 54–65°C — narrower than standard 200TW compounds. Track temperature is already captured in these measured plateau values — a 10°C hotter track raises plateau ~3–5°C, which the gas law automatically compensates for. Eastern Creek CCW measured plateaus: FL ~58°C · FR ~61°C · RL ~46°C · RR ~52°C.

Tip: outside tyres (right on CCW, left on CW) run 4–6°C hotter · Track temp +10°C ≈ plateau +3–5°C

Calculated Cold Pressures (psi)

Corner Loads & Tyre Specification

Static Corner Weights

Tyre Specification

Contact Patch Estimate — Static at Hot Pressure

Approximated from load ÷ pressure. Useful for relative comparison between corners and axles.

Session Iteration

Session Scaling — Enter Actual Results (psi)

Enter what you set cold and the hot plateau you measured immediately on pit entry.
Scaling factor = actual hot ÷ actual cold. Next cold = target hot ÷ scaling factor.
Tolerance: ±0.5 psi = good · ±1.0 psi = acceptable · >1.0 psi = must correct.

Corner	Cold set	Actual hot	Target hot	Scaling factor	Next cold (psi)	Status

Calibrated Scaling Factors — Eastern Creek CCW

Measured scaling factors — Honda EK Civic · Eastern Creek CCW · 3 sessions

Corner	Sess 1 Qual	Sess 2 Race	Sess 3 Eve	Recommended SF	At 32 psi hot	At 30 psi hot	At 28 psi hot
Front left	1.332	1.259	1.275	1.275	25.1 psi	23.5 psi	22.0 psi
Front right ★	1.381	1.358	1.354	1.364	23.5 psi	22.0 psi	20.5 psi
Back left	1.179	1.152	1.152	1.155	27.7 psi	26.0 psi	24.2 psi
Back right	1.213	1.217	1.240	1.223	26.2 psi	24.5 psi	22.9 psi

★ FR is most consistent across all three sessions (spread of only 0.027). This is the most reliable scaling factor — verify first when running at a new circuit or after an ambient temperature swing >10°C.

Recommended cold starts — Eastern Creek CCW at 32 psi hot target

Front left

25.1

psi cold → ~32 hot

Front right ★

23.5

psi cold → ~32 hot

Back left

27.7

psi cold → ~32 hot

Back right

26.2

psi cold → ~32 hot

Why lower than RE71RS nominal: Three sessions show the EK Civic is faster at 27–32 psi hot than 33+ psi. The RE71RS Super 200 compound requires the tyre to be in its temperature window before higher pressures are beneficial. Fronts have cold outer shoulders (41–48°C) and rears are below the 54°C optimal window. Fix temperature first — increase FL negative camber toward −4.3/4.5°, change rear toe from −2.8mm to +1.0mm toe-in — then targets can move toward 32–34 psi.

Pyrometer Temperature Analysis

Based on Samir Abid / Your Data Driven pyrometer interpretation framework. Enter your three-zone tyre temperatures (Outside / Middle / Inside) for each corner immediately on pit entry (<30 sec). The analyser computes inflation diagnosis, camber spread, temperature window status, and front-to-rear balance — and flags the priority action for each corner. Outside = towards kerb. Inside = towards car centre.

Analysis targets

Target avg temp (°C)

Window ±°C

Front camber target spread (°C)

Rear camber target spread (°C)

Inflation tolerance (°C)

Target avg temp is your session target for average tyre temperature. RE71RS race target: 80°C ±5°C (75–85°C). Qualifying target: 90°C ±5°C. Note: the RE71RS compound activation window (54–65°C surface) is different — it is a carcass surface threshold, not the lap-time-optimal working temperature. Camber target spread is the inner-minus-outer temperature difference you are aiming for — RE71RS with our Civic setup: 8°C front (−4.0°/−3.7° camber), 4°C rear (−3.2°/−2.9° camber). Post-alignment June 2026 values. Inflation tolerance is how many °C centre-vs-edge heat difference is acceptable before flagging under/over-inflation. 5°C is a good starting point. Pre-filled with YDD Optimiser calibration values for RE71RS at Eastern Creek CCW.

Corner temperatures — Outside / Middle / Inside (°C)

Per-corner diagnosis

Car balance summary

Interpretation method — Samir Abid / Your Data Driven framework

Diagnostic	Method	Result
Temperature window	Average of O/M/I readings compared to target ± window	Cold / OK / Hot
Inflation	(Inner − Middle) minus (Outer − Middle). If equal → OK. Positive → overinflated (middle runs hot). Negative → underinflated (edges run hot).	Under / OK / Over
Camber spread	Inner − Outer temperature. Compare to target spread. Positive means inner hotter (negative camber effect). On FWD front, some positive spread is also a drive torque signature.	Too Little / OK / Too Much
Front-to-rear balance	Average of all 4 front readings vs average of all 4 rear readings. Large differential (>20°C on FWD) indicates axle load/drive torque imbalance.	F-heavy / Balanced / R-heavy
Left-to-right balance	Average left side vs average right side. On RHD cars, right side expected to be slightly warmer due to driver weight. On CCW circuits, right side outside tyres run hotter.	L-bias / Balanced / R-bias

FWD front inner heat warning: On a FWD car, inner-hotter-than-outer on the front axle has TWO possible causes: (1) insufficient negative camber, and (2) drive torque loading the inner edge on corner exit. Do not automatically add negative camber without checking whether the inner heat is worse after high-traction corners vs low-traction corners. The RE71RS stiff carcass makes it especially sensitive to camber — but also to overdriving on exit.

Tyre Profile Settings

Compound Presets

Select a known compound to load its typical working parameters as a starting point. You can then fine-tune in the Custom Profile section.

Note: Preset values are community-sourced estimates — not manufacturer data. Treat them as starting points and calibrate from your own session data. Your measured plateau temperatures are always more reliable than any preset.

Custom Profile — Edit & Fine-tune

Compound / tyre name Bridgestone RE71

Treadwear rating / category 200TW

Surface Temperature Window (°C)

Lower limit — compound too cold below this

°C

Upper limit — grip drops above this

°C

Cold <54°C Optimal 54–65°C Overheating >65°C

Working Hot Pressure Range (psi)

Lower limit — too soft, excess sidewall flex

psi

Upper limit — tyre becomes greasy above this

psi

24 psi Working range 28–34 psi 36 psi

Notes / characteristics

How this profile affects the calculator

Compound Reference — Community Data by Category

Important distinction: All compounds below carry a 200TW UTQG rating, but "200TW" spans two very different subcategories. Super 200 competition tyres (RE71RS, A052, Vitour P1) are high-grip, narrow-window compounds designed primarily for circuit and time-attack use. Standard 200TW tyres (RT660, RS4, Falken) are softer, more tolerant compounds designed for mixed street and track use. They behave differently on track — particularly in how they respond to temperature and pressure — and should not be treated as equivalent.

Super 200 — Competition-oriented DOT tyres (200TW UTQG)

Compound	TW	Category	Opt. surface temp	Opt. hot pressure	Warm-up	Key characteristic
Bridgestone RE71RS ★	200	Super 200	54–65°C	30–34 psi circuit	<1 lap	Narrow operating window. Stiff carcass, soft tread blocks. Intolerant of slip — punishes overdriving. Gets faster as tread wears (less squirm). Greasy above ~36 psi. Camber sensitive. Faster in wet than expected.
Yokohama Advan A052	200	Super 200	50–65°C	30–35 psi circuit	<1 lap	Very low activation temperature — works almost cold. Needs wider wheels and more camber for best performance. Slower to cool once overheated. Best on lighter cars with high camber.
Vitour Tempesta P1	200	Super 200	52–67°C	30–35 psi circuit	<1 lap	Fast warm-up. More heat-tolerant than RE71RS over multiple hot laps — better for circuit endurance. Slight heat soak on long stints, but recovers on straight. Cost-per-lap leader in GRM long-term testing.
Nankang Sportnex CR-S	200	Super 200	52–68°C	30–35 psi circuit	1–2 laps	Budget-friendly Super 200. Slightly behind RE71RS and A052 at full tread but closes gap as it wears. GRM long-term testing showed consistent pace at mid tread depth.

Standard 200TW — Mixed street/track DOT tyres (200TW UTQG)

Compound	TW	Category	Opt. surface temp	Opt. hot pressure	Warm-up	Key characteristic
Toyo Proxes RT660	200	Standard 200TW	55–70°C	32–36 psi circuit	1–2 laps	Wider temperature window than Super 200s. More forgiving of overheating and undertemping. Better street manners. Good longevity for the category.
Hankook Ventus RS4	200	Standard 200TW	55–70°C	32–38 psi circuit	2–3 laps	Prefers higher pressure and higher temperature than RE71RS. Slower warm-up but longer tread life. More tolerant of sustained circuit running.
Falken Azenis RT660	200	Standard 200TW	55–68°C	32–36 psi circuit	1–2 laps	Similar platform to Toyo RT660. Good balance of grip and wear. More predictable at the limit than Super 200s.
Continental ExtremeContact Force	200	Standard 200TW	55–70°C	33–38 psi circuit	2 laps	Higher pressure preference. Excellent consistency across a full race stint. More street-focused behaviour.

Other categories — for reference

Compound	TW	Category	Opt. surface temp	Opt. hot pressure	Warm-up	Key characteristic
Hard R-compound / Slick	~40–80	R-compound	75–110°C	38–44 psi circuit	3–5 laps	Requires significant heat input to reach window. Much higher pressure range. Samir Abid's generic tyre temperature table (65–95°C peak grip) maps to this category — not to 200TW compounds.

★ RE71RS — why it belongs in Super 200, not standard 200TW: Despite sharing the 200 UTQG rating with street-oriented 200TW tyres, the RE71RS behaves more like a competition tyre. It has a narrower operating window, is more sensitive to pressure, punishes overdriving, and improves as tread wears due to reduced squirm — characteristics of a proper competition compound. The generic "200TW" community pressure data (e.g. 33–36 psi hot) primarily originates from standard 200TW testing and is not directly applicable to the RE71RS in all conditions.

All values are community-sourced estimates. Manufacturer engineering data is not publicly available for any of these compounds. Your own session measurements always take priority.

Bridgestone RE71RS — Compound Notes

RE71RS compound characteristics — Super 200 competition DOT (200TW UTQG)

Classification: Super 200 competition compound. The RE71RS carries a 200TW UTQG rating but belongs in the Super 200 competition subcategory alongside the A052 and Vitour P1 — not with street-oriented 200TW compounds (RT660, RS4, Falken). It has a narrower operating window, stiffer carcass, softer tread blocks, and improves as tread wears. Generic "200TW" pressure data from the internet primarily originates from standard 200TW testing and is not directly applicable to the RE71RS.

Parameter	RE71RS nominal	EK Civic actual (Eastern Creek CCW)
UTQG treadwear	200TW	—
Classification	Super 200 competition DOT	—
Optimal hot pressure	30–34 psi circuit (Super 200 range)	28–32 psi faster — compound below temp window on FWD; lower pressure compensates
Optimal surface temp	54–65°C (narrow window vs standard 200TW)	FR best: 56–59°C ✅ · FL outer: 41–48°C ❌ · Rears: 38–57°C mixed
Carcass character	Stiff carcass, soft tread blocks — punishes overdriving	Confirmed — clean line mandatory; scrubbing in understeer reduces grip sharply
Wear behaviour	Gets faster as tread wears (less tread squirm)	New tyres may feel slower than worn tyres — normal for Super 200 class
Warm-up time	<1 lap	Fronts reach window within 2 laps. Rears may not reach 54°C on CCW passive axle.
Camber requirement	High — needs more than standard 200TW	Post-alignment (Jun 2026): FL −4.0°, FR −3.7°. New baseline — re-verify FL outer temp after first session. Consider −4.3° to −4.5° if FL outer still cold.
Front/rear toe	Mild front toe-in, rear toe-in recommended	Post-alignment (Jun 2026): Front toe −2.5mm total toe-in (corrected from prior 11mm toe-out); Rear −2.8mm total toe-in (maintained). Alignment: Cox Automotive 19/06/2026.
Pressure sensitivity	High — 1 psi noticeable (narrower window than standard 200TW)	Confirmed — 1 psi difference felt clearly in car behaviour.
Wet performance	Better than expected for the category	Adequate in damp. Not a wet tyre.

Pyrometer interpretation — RE71 on EK Civic CCW

Reading	State	Action
FL outer cold (41–48°C), inner warm (58–64°C)	Drive torque inner loading — camber insufficient	Increase FL negative camber to −4.3° to −4.5°. Do not raise pressure to compensate.
FR even 56–59°C all zones	✅ Optimal — reference corner	Maintain current setup.
Rears below 54°C	Below RE71 window — passive axle	Reduce rear cold pressure 0.5–1 psi. Add rear toe-in to improve load efficiency.
Centre hotter than edges	Overinflated for thermal state	Reduce cold set 0.5–1 psi.
Edges hotter than centre	Underinflated	Increase cold set 0.5–1 psi.

Setup priorities — EK Civic to improve tyre temperatures

Priority	Change	Expected effect
✅ Done (Jun 2026)	Front toe corrected → −2.5mm toe-in (was 11mm toe-out)	Removes scrub heat from straights; tyre builds temp from cornering load rather than scrub. New scaling factors needed after next session.
✅ Done (Jun 2026)	Rear toe → −2.8mm toe-in (maintained)	Stabilises rear under load. Confirmed by alignment sheet.
1 — Next session	Re-run scaling factor calibration with new alignment	Front toe change affects tyre load and thermal behaviour. Current scalings (FL 1.275, FR 1.364, RL 1.155, RR 1.223) are pre-alignment and should be re-verified.
2 — Monitor	Check FL outer temp with new alignment	Previous sessions showed FL outer at 41–48°C (below 54°C window). Toe-in change may improve warm-up. If still cold: increase FL camber to −4.3° to −4.5°.
3 — Pending result	Once FL spread <10°C: raise front hot target to 32–33 psi	When tyre is in temperature window, correct pressure unlocks full RE71 grip. Not meaningful until tyre is in window.

Vehicle Comparison

EK/EM Civic FWD vs E36 318is RWD — Bridgestone RE71RS (Super 200)

Parameter	EK/EM Civic FWD	E36 318is RWD
Weight (car + driver)	1100 kg / 2425 lb	1150 kg / 2535 lb
Weight distribution	62% F / 38% R	49% F / 51% R
Front axle load	682 kg / 1504 lb	564 kg / 1243 lb
Rear axle load	418 kg / 921 lb	587 kg / 1294 lb
Drive axle	Front	Rear
Front tyre	225/50R15 RE71	245/45R17 RE71
Rear tyre	205/50R15 RE71	245/45R17 RE71
Hot target — front	30–32 psi (data-calibrated, Eastern Creek)	31–33 psi
Hot target — rear	30–32 psi (passive, runs cool)	31–34 psi (driven axle)
Front surface temp (race)	FR 56–59°C ✅ · FL outer 41–48°C ❌	55–60°C both sides ✅
Rear surface temp (race)	38–57°C — below window	60–65°C — in window ✅
RHD priority corner	FR — driven + braking + driver	RR — driven + driver + diff
Rear warm-up concern	Yes — significant at Eastern Creek CCW	No — rears run hot from drive torque
Primary wear (RE71)	FL outer shoulder	RR outer shoulder
Camber — front	FL −4.0° (increase) · FR −3.7°	−2.5° to −3.5°
Rear toe	−2.8mm toe-out (change to toe-in)	Mild toe-in standard

First session starting points — RE71 · 24–36 psi slider range

Vehicle / Corner	Cold start	Expected hot	Note
Civic FL	25.1 psi	~32.0 psi	CCW inside front. Monitor outer temp >50°C.
Civic FR ★	23.5 psi	~32.0 psi	CCW outside front. RHD priority corner. SF 1.364.
Civic RL	27.7 psi	~32.0 psi	Passive. Higher cold compensates for cool plateau.
Civic RR	26.2 psi	~32.0 psi	Passive. Reduce 0.5 psi if rears feel wooden.
E36 FL	26.5 psi	~31.5 psi	Braking only. Cooler than rear.
E36 FR	26.5 psi	~31.5 psi	RHD driver weight, not driven.
E36 RL	25.5 psi	~32.5 psi	Driven. Hotter plateau → lower cold start.
E36 RR ★	25.0 psi	~32.5 psi	RHD + driven. Heaviest and hottest tyre.

★ = RHD priority corner. Starting points only — use Session Iteration to converge on exact scaling factors for your conditions.

RHD cross-weight note

Both cars are RHD. Driver sits on the right. Civic: engine and driver both right-side — FR is heaviest corner. E36: driver and differential are both right-rear — RR is heaviest. Target 50/50 diagonal cross-weight as baseline. A 0.5–1 psi cold pressure offset right-to-left may compensate for driver-side imbalance.