by fungus » Mon Apr 01, 2013 8:29 pm
I've never had mine chipped but I believe Sodatezzer on this forum has a chipped Skoda Fabia diesel. This would probably see your insurance premium shoot through the roof though, and what the effect on fuel economy would be I couldn't say, but the weight of the right foot would probably have the biggest effect.
Diesels have higher gearing than petrols, and I found that in my Ibiza in most circumstances, it was 3rd in a 30, 4th in a 40, only using 5th at speeds above 50 depending on the type of road, eg. flat straight NSL. On a fast twisty NSL I would probably use 4th not 5th, or maybe 3rd if there was very little distance between bends.
Diesel engines differ as well. My wife has just replaced her 2.0L Peugeot 306 HDI estate with a 1.6L Skoda Octavia estate. They both drive differently, and although the Octavia has a smaller engine, it is more powerful. It will plod along happily in 4th at 30mph although there is little throttle response, you need to drop down to 3rd or 2nd for that. The 306 and my old Ibiza would not drive happily in 4th at 30mph, and were much happier in 3rd. The Octavia has a gear selection indicator which will indicate the most suitable gear for economy when driving using a very light throttle setting, this tends to be over-ridden most of the time though, but it does recognise when you are pushing on by not indicating a gear change.
Personally, I would try using different gears, in different situations when safe, to find out what the most suitable gear is, and not to be too tied to what your driving instructor has told you as many instructors are very eco minded, and this style of driving will not be the most responsive. Also many driving school cars have small low powered engines with lower gearing. So my advice is to get out and see how your car responds, and be guided by what you feel.
Nigel ADI
IAM observer