Terraclean as seen on Wheeler Dealers

[doorman]

jonmark said:

I had my 2004 Saab93 1.9tid recently at Jubilee garage Shotton Deeside for a Terra Clean. Prior to the clean i was getting 42mpg , after the clean im getting 34.5 to 36mpg i have no idea why and no reply from the garage, is this supposed to happen?

That is NOT consistent to any other Terraclean feedbackI have heard, please contact Terraclean direct for their view. However, how did you find the power gain in comparison