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Summary
| Description |
English: The force necessary to overcome en:hysteretic losses in a rolling tire is known as en:rolling resistance. This parameter became important to USA vehicle manufacturers with implementation of C.A.F.E. (Corporate Average Fuel Economy) standards for new cars. It is measured by placing load cells in the wheel spindle and measuring the rolling resistance force in the horizontal (longitudinal) direction. It requires precise instrumentation, calibration, speed control and equipment alignment for repeatable results. Rolling resistance is usually expressed as a coefficient: resistance force per 1000 units of load. OE passenger car tires designed for fuel efficiency may have coefficients in the range 0.007 to 0.010 when fully inflated and evaluates at thermal equilibrium. The test load, speed and inflation pressure vary according to the vehicle manufacturers’ requirements. Rolling resistance is significantly influenced by inflation pressure, as illustrated in the figure. Since tire rolling resistance can consume up to 25% of the energy required to drive at highway speeds, it is economically wise to keep tires inflated properly.
Deutsch: Die zur Überwindung des de:Hystereseverlusts eines Fahrzeugreifens notwendige Kraft wird als de:Rollwiderstand bezeichnet. Mit der Einführung des C.A.F.E. (Corporate Average Fuel Economy) Standards für Neuwagen gewann dieser Parameter Bedeutung für US-amerikanische Fahrzeughersteller. Die Messung des Rollwiderstands in horizontaler Richtung (Längsrichtung) erfolgt durch eine de:Kraftmesszellen in der Radachse. Präzise Messinstrumente, Kalibrierung, Einhaltung der Geschwindigkeit und Abgleich der Messausrüstung sind notwendig, um reproduzierbare Ergebnisse zu erhalten. Der Rollwiderstand wird normalerweise als Koeffizient angegeben: Kraft pro 1000 Belastungs-Einheiten.
Erstausrüstungs-Leichtlaufreifen von Personenkraftwagen erreichen bei vorgesehenem Luftdruck und Betriebstemperatur Koeffizienten im Bereich von 0,007 bis 0,010. Belastung, Geschwindigkeit und Luftdruck bei den Testläufen variieren jedoch je nach Vorgabe der Hersteller. Der Rollwiderstand wird maßgeblich vom Reifendruck beeinflusst, wie im Diagram zu erkennen ist. Da der Rollwiderstand bis zu 25% des Energieverbrauchs bei Geschwindigkeiten von um die 100 km/h ausmacht, ist es ratsam, den Luftdruck regelmäßig zu kontrollieren. |
| Date | |
| Source | Gent, Alan N. (2006) The Pneumatic Tire, DOT HS 810 561, Washington, DC: National Highway Transportation Safety Administration |
| Author | Employee of the U.S. Department of Transportation |
Licensing
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This work is in the public domain in the United States because it is a work prepared by an officer or employee of the United States Government as part of that person’s official duties under the terms of Title 17, Chapter 1, Section 105 of the US Code.
Note: This only applies to original works of the Federal Government and not to the work of any individual U.S. state, territory, commonwealth, county, municipality, or any other subdivision. This template also does not apply to postage stamp designs published by the United States Postal Service since 1978. (See § 313.6(C)(1) of Compendium of U.S. Copyright Office Practices). It also does not apply to certain US coins; see The US Mint Terms of Use.
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| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 22:51, 15 December 2022 | | 1,295 × 746 (77 KB) | Hohum | Optimise space use |
| 14:51, 5 May 2019 |  | 1,446 × 828 (95 KB) | HopsonRoad | User created page with UploadWizard |
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