Tag: Fuel Efficiency

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Snapshot: effect of tire pressure on rolling resistance

metrompg.com series | Highlighted on Fuelcons

In this further post published on metrompg.com, the impact of tire pressure on rolling resistance was assessed using two different vehicles: a 1998 Pontiac Firefly (Geo Metro) and a 1999 Toyota Camry. The experiments were conducted on a paved slope with flat run-out. The methodology involved inflating the tires to different pressures (20 PSI [1.38 bar] to 60 PSI [4.14 bar]) and then letting the cars coast down the slope with engine off, transmission in neutral, and brakes released. Distances to marked “stop points” were measured using a distance measuring wheel (some kind of).

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Reflections on side mirrors: testing drag vs. MPG

metrompg.com series | Highlighted on Fuelcons

This experiment, which was published on metrompg.com, aimed to explore the influence of side mirrors on a vehicle’s drag and fuel efficiency. The motivation behind this study stemmed from the adoption of video cameras instead of conventional side mirrors in high-efficiency concept cars, leading to a desire to ascertain whether such alterations yielded tangible advantages. The investigation was carried out using a “Blackfly,” essentially a black Pontiac Firefly, wherein the stock non-folding driver’s side mirror was replaced with a folding mirror from a 1993 Suzuki Swift 3-door, featuring an aerodynamically optimized hinge.

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