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Quote: Originally posted by Monty15 on 10/7/2024

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Probably depends on what the re-map prioritised - more power, different peak power/torque points, power band characteristics, etc. etc.! Some people like their driving to be sedate and have torque at low revs do the work, whilst others are wannabe racers and love all the power at near red line revs! The standard map for the car will have been heavily biased to economy/low emissions at the standard test figure/speeds used to assess the car's rating for economy and emissions used to judge it against the competition and for taxation bands.

It may have shifted the sweet spots for economy away from engine speed at normal towing speeds. It may have shifted those sweet spots in terms of any particular gear, so you may need a lower gear to climb hills than before, or vice versa, you may be dropping a gear when you no longer need to!

I've got friends who remap their engines regularly on their track day cars (they DIY trackside with reprogrammable ECUs and a laptop), it's not about economy with them, it's about matching power bands, peak power/torque to track speed/gears on any particular track. But the principle remains the same for a road car, maybe your re-map is not best suited to towing. It's a complicated business and a little bit of a black art, friends apply a lot of technical theory to it, but sometimes a bit of trial and error triumphs over all!

It's difficult to say whether a re-map can be done to better towing performance/economy or not, that's best for experts to discuss. As to whether you should go back to the original map, that rather depends on why you had it re-mapped in the first place, you've got to balance your towing miles (and reduced economy) against solo driving miles and whether the re-map enhances that in any way.

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Quote: Originally posted by Colin21 on 11/7/2024

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One of the things I like with my outfit is that there is no noticeable difference in fuel consumption whether the caravan is on the back or not. I have sometimes thought about having the car remapped, but then I've thought better of it. There are so many different options, so what would I go for?

I have often wondered how anyone would know if their car had already been remapped? In my boy-racer days most of my cars were got-at in some way. Twin-carbs, free-flow manifolds, skimmed heads etc, but these were all obvious. These days unless there are stickers to the effect that a mod has been done, you simply can't tell. I always had a feeling that my last car, a 2007 Hyundai Tucson automatic, had been got-at in some way as it seemed to be much quicker off the mark than standard ones, and it was all too easy to spin the wheels when pulling away quickly. I have a roundabout right near me which is a nightmare! The traffic comes round it in a fast continuous stream, so you take your life in your hands getting out of the turning from my village, and that Tucson nearly always spun its wheels pulling out of there.

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Quote: Originally posted by clbewi on 10/7/2024

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How are you measuring your mpg?
Don’t rely on the cars on board computer

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Quote: Originally posted by Grayhair on 11/7/2024

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I'm using the Renault Rlink 2 system, which I guess is linked to the on-board computer.
So why do you say not to rely on it, isn't it accurate?

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Quote: Originally posted by Grayhair on 11/7/2024

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Quote: Originally posted by Colin21 on 11/7/2024

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One of the things I like with my outfit is that there is no noticeable difference in fuel consumption whether the caravan is on the back or not. I have sometimes thought about having the car remapped, but then I've thought better of it. There are so many different options, so what would I go for?

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You are lucky if there is no appreciable change in consumption, your outfit is obviously well matched. In my case the original was 53.8mpg without caravan and 36mpg with it, quite a drop. And I know the car was never modified because I got it straight from the factory, but that's a different story.
With the remap the consumption dropped to 25mpg pulling the caravan, I'm not sure what it is without the van. I should add I'm speaking North of Scotland roads which leave a lot to be desired.

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Quote: Originally posted by Colin21 on 11/7/2024

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....

..... However, my car itself is rather brick-like and quite high so I think a lot of the air-flow goes over the caravan roof. A lower, less powerful car than mine towing the same caravan would probably notice a much bigger difference than I do.

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