My 2009 Clubman S used to average 33-35 mpg. After replacing my engine, I'm now only seeing about 28 mpg with all other factors being equal. I thought it might be engine break in, but after a couple thousand miles on the new engine, there has been no improvement.

Is this to be expected? Or is there some programming that could have caused the decrease in mpg. Ideas? Any way to "fix" this?

I also notice less turbo blow off noise when I let off the throttle. I liked hearing the "pheeeeeeeeew" noise and miss it.

 

Was the entire engine replaced or was it rebuilt? Was it replaced with a new engine or a rebuilt or a used engine?

 

Entire engine was replaced with a "new" remanufactured engine from MINI.

 

Interesting... Hard to say why the gas mileage has gone down. There are so many factors that affect gas mileage. Is the engine the only thing that has changed on the car? Have you switched to new tires or anything like that? The engine should have a 2 year warranty from mini so you should be able to take it in and ask them about it. Is it idling rough or anything like that?

 

A new engine is very tight and will take some miles to loosen it up. I will bet after a few thousand miles the MPG will pick up.

 

It does have a little vibration at idle sometimes.

No other changes apart from the engine.