Ask Honest John

Most recently answered fuel economy questions
I have recently taken delivery of an Audi Q5 2.0 Tdi STronic and whilst delighted with most aspects of the car, fuel consumption is disappointing. I've done several long journeys, mix of motorway, A &...
Please could you give me some advice on what car to buy? Ideally, I'd like a new or pre-registered either BMW 520d, or an Audi A4/A6 diesel. I've got £24k + trade in to play with. Or, reading that you've...
My wife and I test drove the Hyundai i30 Comfort 1.4 petrol and 1.6 CRDi diesel last Sunday, and preferred the diesel for its power, lower emissions, taller gearing and motorway cruising. The problem is...
I have a BMW 123d and am looking at ways to further decrease my fuel consumption as I drive approx 100 miles per day, mainly all motorway sat on cruise control at 70. I see these Bluefin Superchip units...
My question arises out of the discrepancy revealed by all road tests I have seen between official fuel consumption figures of hybrid cars and those found by road testers. These appear to be far larger...
I tried Shell V-Power to see if it made any difference to mpg, largely because of your newspaper column. I drove back to the UK from Frankfurt in my 1998 Merc CL500 last week, averaged 136km per hour,...
I purchased a demonstrator Mercedes A180CDI auto with 9,500 miles in late June from a main dealer and have put on a further 6,000 miles. The fuel economy has always been disappointing, averaging 41.2mpg,...
Seeing you refer to the Hyundai i20 returning "more than 50mpg" I wondered if it has the same 1,248cc engine as our recently purchased i10. Our only disappointment with this excellent little car is the...
I’ve just taken delivery of a 2008 BMW 535d Touring with only 600 miles on the clock. The consumption readout says 30mpg at 60-70 mph on the motorway. My previous 2007 335d Touring (pre-Efficient Dynamics)...
You may recall I wrote to you having purchased a Mitsubishi Outlander 2.2 diesel on the mpg representations made to me. I took the case to court on 8th December 2008, Case no 8SN01238 and won the case....