Hi all, we recently purchased a 2001 ML 270 for towing our caravan after reading a number of positive reviews and experiences. It certainly tows the van well, but we took the pair out for a long trip this last week as a test run, and the fuel consumption seemed odd. When we first started, the car was doing an average of 13.5 litres/100kms (17.5 mpg) for the first ~100kms. The fuel consumption steadily rose after that (consistently in very similar driving conditions) to 17 l/100kms (14 mpg) over the next 700kms. This was confirmed through working out manually filling the tank, etc. It then remained at 14mpg over the remaining 800kms of our round trip. On a flat, straight road, I played around with different speeds and found the fuel consumption as follows (using the on-board fuel consumption read out): 60kph - 10.5 l/100kms 70kph- 12.5 l/100kms 80kph- 15.5 l/100kms 90kph- 16.5 l/100kms This was pretty consistent and it was a fair test, no wind, flat road for around 100kms (central Victoria, Australia), middle of the day in 25 degree Celcius, low humidity. I recently drove the car without the van and experienced something similar. I drove around 1500kms, and the first 500kms the car averaged 8.3 l/100kms, (28 mpg) but dropped to 10 l/100 kms (23 mpg) after that for the remainder of the trip. Tyres all at 32PSI, car has done 260k, but used no oil, water, etc. Running temp was around 90 degrees C, very consistent. Can anyone suggest a possible cause for this? Any home diagnostics I can perform? Thanks in advance.