Expert: Bill Milbert - 2/1/2010

Question
QUESTION: I have a 2008 Honda Civic Si Coupe and just last week, I had the front shocks/struts replaced under warranty due to this noise in the steering wheel.  As soon as I got the car back, my last two tanks of gas, my fuel efficiency dropped drastically.  Since my car is equipped with a digital gas meter, over the past 3 years of ownership, it always drops a bar of gas around the same mileage (I reset the Trip Mileage every tank).  The weather, my driving habit and tire pressure all remain the same before and after the warranty work.  I am 100% sure of that.

What can I check or could've went wrong with the front shocks/struts replacement that can affect fuel efficiency??

Thanks so much for your help!  

ANSWER:  Fred,
 The only conclusion I can come up with in your case here would be a wind co-efficient factor.
When shocks,struts and various other suspension parts are replaced. The vehicle may sit a bit
taller or higher than before, thus causing an increase in wind drag,however slight this would
effect fuel economy.          Hope this helps. Bill

---------- FOLLOW-UP ----------

QUESTION: Thanks Bill!

That was my only guess as well, but would it affect the fuel efficiency by roughy 20% (from 8L/100km to 9L/100km... I'm getting about 100km less per tank).  If so, how long do you think it'll take before the struts settle in so I can see my regular mileage?

Answer
This is kinda like calling a doctor and telling him you have a pain and expecting a cure over
the phone.Without a check-up or in your case the right diagnostics by a good mechanic.
Sorry Fred, but I'm scratching my head as well on this one.
I think maybe you might want to try another category. My knowledge is in heavy collision/frame
repair and reconstruction/body and paint specifics.     
         Best of luck Fred.    Bill