Three-quarters of Australia’s new cars use more fuel than advertised lab rating, testing shows

Comments

• slazer2au@lemmy.world ⁨3⁩ ⁨weeks⁩ ago

  Is that really surprising? The ratings are in ideal conditions when people do not drive like that.

  I remember an offhand comment Jeremy Clarkson made on Top Gear where you look at the city driving number, the worst L/100K, as that is what you should expect when driving on a highway when it is suppose to be most efficient.

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  • pHr34kY@lemmy.world ⁨3⁩ ⁨weeks⁩ ago

    I remember when Clarkson drove a BMW 5 series and a Prius around the test track flat-out, and they consumed similar amounts of fuel. Their labels showed the Prius was meant to use much less.

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    • Longmactoppedup@aussie.zone ⁨3⁩ ⁨weeks⁩ ago

      It was a Prius being driven as fast as it could go for 10 laps around the Top gear test track. Being followed at the same speed by an E9x M3.

      Entertaining yes. Scientific… Hrm

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  • Salvo@aussie.zone ⁨3⁩ ⁨weeks⁩ ago

    Regulators are creating a Rat Race of fraudulent testing and claims of compliance.

    This is going to be DieselGate all over again.

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• Salvo@aussie.zone ⁨2⁩ ⁨weeks⁩ ago

  Part of this is Speedometer calibration.

  Fuel consumption is calculated in lab conditions, using an externally arbitrated distance and the fuel consumed is also measured under lab conditions.

  Speedos will never be 100% accurate so manufacturers make sure that the error is conservative. Someone being charged with speeding when their speedo was exactly on the speed limit would be bad press. Most new cars are travelling at about 90-95km/h in 100km/h zones.

  Petrol expands and contracts as it changes temperature. This is a good reason to only fill your tank on cold days, in the morning. (Although the cost difference is not worth considering, the difference in volume of fuel is measurable.

  Finally, the fuel pump flow that is measured in your EFI system and the diameter of your tyres are also affected by temperature.

  These three factors affect what your fuel gauge tells you. You may be travelling 100km and using 5.6l, but your ECU may be calculating and displaying a higher result.

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• Tau@aussie.zone ⁨3⁩ ⁨weeks⁩ ago

  I get the claimed figures on both my car and van so it’s not like hitting them is impossible, but it is highly dependent on how and where you drive. Many people drive with the smoothness and ability to look ahead of a myopic orangutan (e.g. accelerate hard, immediately jump to brakes, back to acceleration, repeat) but even with a bit of care there’s only so much you can do if your driving involves a lot of short trips and stop start traffic.

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