Introducing our new Real MPG iPhone app: Find out more | No thanks
Ask a Question

What's your question? Search here

Is there a defeat device in my Porsche Macan as with the Volkswagen EA189 engine?
I have a 2014 Porsche Macan 3.0-litre diesel, bought new. It recorded 42mpg or better on a long run and 39mpg average on short urban runs. Porsche wrote asking for the car to have a software update for emissions. I was very suspicious about this and received written assurances from Porsche UK that the fuel consumption would not be affected. But the mpg has fallen dramatically on short runs to 33mpg and on the long runs to 37mpg. I feel duped by such a prestigious company. Is there evidence that a defeat device exists in this particular device as per the Volkswagen situation?

Asked on 17 May 2017 by Peter Jones

Answered by Honest John
Less widely publicised than the 4-cylinder EA189, but yes. It's basically an Audi engine, subject to the NOx emissions fix. Reducing NOx creates more soot and active regeneration of the DPF requires more fuel, but readers have found that the system works a lot better on Superfuels such as Shell V-Power Nitro Plus or BP Ultimate, which you should be using anyway.
Dear Honest John,

Please help me choose my next car. I would like it to have:
    Select a few terms below
Similar questions
My Skoda Yeti 2.0 TDI had the emissions update six months ago. I have since discovered a drop of 6.5mpg. Skoda say they cannot do anything, can anyone...
Soon after the emissions update our Skoda Yeti 2.0 TDL had to have a new ERG recirculating valve fitted at huge expense. Luckily, we we covered but this...
I've had the emissions fix done on my SEAT Leon and now the car is a dog. Can Volkswagen reinstate the old engine remap and remove the flow obstructer...
Related links
Everything you need to know about how the emissions scandal affects you.
Real MPG enables you to register the fuel economy you are actually getting against your make and model of car, its engine and type of transmission. Every time you enter an average consumption figure against your car, the overall average automatically adjusts to reflect it.
Related models
Sublime handling even on rough British roads. Impressive performance from all engines. Excellent build quality. Practical family car.

Ask Honest John

Value my car

Amount to borrow
Sorry. The minimum loan amount is £1000
To pay back over

My credit score

Best available rate 9.20%

Total repayment £9,304.93

Total cost of credit £1,804.93


60 monthly payments

Apply now

Representative example

The Representative APR is 13.2% (fixed) so if you borrow £7,500 over 4 years at a rate of 13.2% p.a (fixed) you will repay £199.21 per month and repay £9562.20 in total.