Xantia Hdi - fuel consumption with a tuning box fitted

[rmunns]

I've had my Hdi90 for over 3 years and have always kept an accurate (full-to-full) check on fuel consumption. That's over 40,000 miles.

Three weeks ago I fitted a tuning box and adjusted the setting until I was happy with the improved performance. For this particular car that was setting 8 out of 10.

For long runs the fuel consumption before fitting the tuning box was 50 mpg.

I have just returned from a long journey (400 miles each way; out on Wednesday, back Friday). I recorded fuel usage full-to-full, filling at destination and also on returning home.

I'm so pleased that it has got better - 55mpg going, 56mpg returning. Because now the other half is convinced that it will payback.

Maybe the tiny difference between these two figures might be because the outward journey was 'uphill' (destination 1000metres higher from sea level than home).

Overall, then, about 10% improvement.