The ones on Egay for £20-£25, that plug into the fuel temp. (i think) sensor. Resistor in a box...

What do they actually do? Bought one, just to make my own mind up about about them. Stated an increase in in power and better fuel consumption. Didnt notice much extra power, maybe a little bit. But the fuel consumption, went from an average of 45-46mpg, to 58mpg

Tried sitting at 60mph, and averaged 68mpg :eek: And my trip computer is only 1-2mpg out. Gave me a range of 600 miles after driving for 40...

But, will it do any damage? What happens when you underfuel a diesel that much?

I'd recheck your trip computer

Those things have a 50p resistor in them , you can make one in seconds

If I paid 50p for a resistor, i'd be savage!

I got 300 for £5 to sell on ebay in singles for £1 to car people.

Sold quite a few, but got bord of selling them after 90 or so. lol.

Dave

When i bought my car, it had one of these "boxes" in it. 3 weeks later i had to replace the fuel temp sensor and another couple of things.

Could be totally unrelated or the thing could have caused the problem..........

Save the pennies n get either a proper "tuning box" or a dirty big remap lol

When i bought my car, it had one of these "boxes" in it. 3 weeks later i had to replace the fuel temp sensor and another couple of things.

Could be totally unrelated or the thing could have caused the problem..........

Save the pennies n get either a proper "tuning box" or a dirty big remap lol

I want a big dirty re-map, but the bank balance says no-no, and the clutch says no-no, which reminds me...

Ive got a proper tuning box in the for sale section.

Dave

I had a dragon box for ages with no issues.

I'd reccomend them to anyone if they cant afford a remap, or are in warranty

Tuning boxes are fine most just increase the fuel pressure which in turn will help get a little more boost , all well and good, i have one on my Merc diesel , its been on for 50k plus and around 6 years , car goes better and is better on fuel.

These resistors just trick the car into thinking its colder than it is so the ecu pumps more fuel in whilst i guess the end result ie more fuel is the same they arent very precise and more than a bit "heath robinson , not worth risking you engine with imo

Its easy to think the car is putting less fuel in and therefore better on fuel but in fact its the opposite , more fuel means more power and therefore you accelerate for less time

More fuel on a diesel also means higher EGT's which if too high can damage the turbo and the engine