WLTP testing standards

JeffL · January 8, 2019

Not sure where on the forum to put this.

A friend of mine has recently bought a new Ford Focus (petrol) and as he does a maximum of 3K miles p.a., all short journeys, he thought he would not have the problems that drivers of diesel cars experience in that their DPFs get blocked-up if the cars are used only for short journeys and are not left running for a little while at the end of a journey to allow for regeneration. However, he's getting a message on the dash which results in him having to run the car for a least 20 minutes at something like 2500 rpm to clear it. So yesterday he went for a drive on the M60 to do this. The message cleared, but this morning when using the car again the message returned. I've told him he'd be better off with an electric car for the exceptionally low mileage he does. I too do lots of short journeys, say 6 miles, but I also do longer ones and total about 6k miles maximum p.a., and would never contemplate a diesel for that and many other reasons.

I only tell the above story as a lead-in to my question, which is, with the most recent WLTP standards, are we likely to have these short-journey problems with new Lexus models? I want a car that doesn't cause me any problems or inconveniences, that's why I run a Lexus. I would only ever buy a Lexus or a Toyota (same thing I know!). If there are going to be problems for short-journey drivers, I'll either stick to my current 2007 car or maybe buy one made before the most recent WLTP standards came in!

Petrol cars have been subject to particulate emissions legislation since the introduction of the EU5 standard in 2009. The latest stage, EU6c, was introduced in September 2017, forcing petrol engine particulate emissions to be reduced by 10 times the previous level.

WLTP (World Harmonised Test Procedure) and RDE (Real Driving Emissions) testing standards. Like EU6c, WLTP applies to all new types of car introduced after September 2017. WLTP should ensure the quoted emissions are much closer to real world outputs.

ColinBarber · January 8, 2019

2 minutes ago, JeffL said:

Not sure where on the forum to put this.

Moved to the correct location 😉

The new emission rules are for new models being introduced, so existing models can continue to be sold without modification for some time. The facelift RC F was affected by this, and they went to full Euro 6d compliance. A Gasoline Particulate Filter was fitted which took away 14 bhp 😞

WLTP means mpg figures should be more real world but you need to be careful when comparing different vehicles in case they are on the two different standards.