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When at first you try to test (update)

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#1 mariner

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Posted 12 April 2024 - 10:12

Everybody spent years slagging off the original EU  fuel economy testing as it was patch over the non CO2 testing protocol


OEM's wated one worldwide fuel economy test regime (WLTP) to sensibly save time and money.


For the WLTP engineers tried very hard to make a single test  requirements across all nations.


The EU then used the WLPT cycle for CO2 reduction legislation.


Now the EU auditors have concluded that the EU implementation of WLTP is in old fashioned words " a crock of ****"


Now i hadn’t realised that the EU required on board fuel economy tracking on all new cars but that is apparently the source of the discovered discrepancy.




I have this feeling the engineers are going to be blamed again!


The EU auditor’s suggestion to follow the UK percent of sales rules for pure EV’s  is fine but that won't really start to bite until 2028 and beyond when EV’s ' must be 52% of sales.



#2 7MGTEsup

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Posted 12 April 2024 - 11:13

I think trying to get real world fuel economy on any driven cycle is difficult as people in the real world seem to accelerate like they are trying to win a race from my experience. Also all the down sized engine in large vehicles start to struggle once you have 4 people in them and a roof box. At 70mph they are probably in component protection the whole time and running at labda 0.9 or worse.


If you drive a car sensibly and keep acceleration levels sensible you can get pretty close to advertised fuel economy numbers. People have to stop thinking you can drive it like you stole it and get the advertised figures.

Edited by 7MGTEsup, 12 April 2024 - 11:15.

#3 Greg Locock

Greg Locock
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Posted 12 April 2024 - 21:13

Any test protocol becomes the target. The only way around this is to switch away from test based designs to design standards that must be adhered to (that's how bridges and office blocks are designed). This will result in less efficient designs.