Are you spending too much on petrol?

The AA recently identified that, compared to a year ago, “a typical 50-litre petrol refill now costs £9.61 more, adding £40.81 to the monthly petrol spend of a two-car family” (http://www.theaa.com/motoring_advice/news/august-fuel-price-report-2011.html) Research at BlablaCar has indicated that 87% of Brits are concerned about the rising costs of petrol, which has made the overall cost of running a car increasingly difficult to manage. This prompted nearly 40% of them to reduce the number of long distance trips they made last year. However, the same reserach showed that only 11% shared their ride to reduce the running cost. More people can reduce the cost of their long distance trip by carpooling. For example, a typical driver on http://www.blablacar.com could save as much as £60 on single trip from Manchester to London.

@klawman I agree with most of what you just said, except the comments about OEM being conservative and the comment about calibration improvements being zero cost. Firstly, OEM have many more factors that they need to balance and also have to warrant their product. Remappers have more freedom to ignore some restrictions placed on OEMs, eg emissions. OEMs have MUCH more stringent emissions limits and measurements than a car in use that has it's annual MOT test (practically a joke compared to what OEMs have to do) so remappers can almost ignore emissions. They also don't usually offer a 60,000 mile warranty for the engines durability or have a useful life expectation of, say, 150,000 miles. So they can increase loadings on engine parts, get closer to the limits of turbo maps etc etc almost without having to pick up the pieces (sometimes literally) if it all goes wrong. Also people who have remaps done will (generally speaking) put up with other niggles in their quest for better power etc. Eg a turbo going into surge would be a MASSIVE problem for an OEM, but probably less so for a remapper. Secondly, any calibration improvement has a cost. There is the development cost, engine tests, legislative tests, etc to be done. Calibration development cost more than most people think, engine testing is not cheap, and the equipment needed to do it on is also extremely expensive.

ECU remapping (or "chipping" as it's usually known) works best on turbodiesel engines, and can offer useful improvements on turbocharged petrol engines. On a turbodiesel, it will increase power, torque and economy (and decrease CO2 emissions), as manufacturers' ECU settings are very conservative (and it allows manufacturers the option to improve performance/economy every time they do a face-lift at zero cost). The downside is that increasing engine power and torque will place more strain on the drive-train (gearbox, final drive, half-shafts, etc) and will accelerate tyre wear on the driven wheels. For naturally-aspirated petrol engines, the gains in performance are very modest and fuel economy is unlikely to be improved. ECU remapping will also void your warranty. Your insurance company will regard the vehicle as "modified" and may increase the premium substantially - or void the policy if they have not been informed. Also be aware that some main dealers routinely re-flash the ECU with the current factory settings every time the car is serviced, thereby over-riding the (expensive) re-map.