I used to get 28-30 mpg when driving on backroads (with a fairly average driving style), since I got the ECU Flash Upgrade and started using the Maxol E5 fuel (both happened the same week) I've found the consumption has dropped off to about 25mpg. prior to that I would have always been using 95 RON Tesco or Texaco fuels.

I was down the country at the weekend so filled up with Tesco 95RON, we done 300 miles and the mpg finished at 29.5ish mpg (some motorway and National roads), average speed 56mph on the clocks so it was clear roads. Now to be honest I would have no problems reaching 35-37mpg before on these type or roads.

Anyone else find this or what do you think the problem might be. The car got its 20k miles service last week and before that I was putting the low mpg down to it being due a service, but at the moment I reakon I'm loosing 5mpg (which is about 60 miles to a tank which is excessive).

I found that E5 returns less mpg. Go back to what you used before and see.

have you tried some vpower?

I found that E5 returns less mpg. Go back to what you used before and see.

That was my plan at the weekend by putting a tank of tesco into it, but didn't find any improvement. It may take a couple of tanks to get the maxol stuff out of its system.

Any ideas if it ain't that ? Someone mentioned Plugs, due to short distances I drive.

have you tried some vpower?

No never tried it

give it a few full tanks of vpower a few long journeys and a few high rev runs in 3rd

There was one other thing which Mcgyver reminded me of that I have tried lately and after reverting back to the old way the consumption has got better. I started using Auto on the Climate Control, going back to Econ it now back to the way it was.

If the car was serviced recently and they changed the air filter, I would have expected a noticable increase in MPG figures. I tend to change mine every 10k miles, and usually see a couple of extra MPG for it.

Using the Aircon on anything other than ECON will decrease your MPG by upto 10%, similar figures apply for rear heated window being on, and driving with window open. Low pressure in tyres is also a common cause.

I still think there are quite a few petrol stations selling 92 RON out of 95 RON pumps.

20k on the octy doesn't include the air filter, neither does 40k.

I notice a drop off at 15k so change them with a genuine part every 10-15k.

You should have the MPG back up in no time at all after a change IMHO