Sudden decrease in MPG
Hello, I have a 1999 156 1.9 JTD . It's done 150,000 Miles and until recently was running well with mpg of 37 mpg for shortish runs and 46 mpg on a long run.
The last week or two I have more like 25 mpg.
I should mention I have had a coolant hose leak which I discovered when the engine temperature suddenly went up. The car is now in the shop to change the hose and diagnose mpg issue.
What could cause a sudden increase in mpg? Could it be related to the hose problem? I have kept the system full of water with the exception of first occasion when the problem was first noticed, then I switched off the engine immediately.
Your feedback is greatly welcome, thanks, Richard