Upgrade Alloys To 17"

[baz_man]

Hi,

Since I had my alloys upgraded from 16” (205/55/16) to 17” (front-225/45/17, rear-245/45/17) I have noticed these issues:

• The MPG has reduced by much more than I expected. I used to regularly reach around 48MPG, however, since having the new wheels fitted, I am struggling to reach 38MPG.
  
• I seem to be able to change up gear around 10mph quicker with the new tyres, compared to the older ones. It’s almost as if the gear ratios have changed!!!
  
• Most garages seem to recommend that if there is more that 2.5% increase in wheel diameter between old and new, then it will effect ride height and gearing ratio. I believe my diameter has increased by 3.2% - should I have anything altered on my car???
  

Any feedback will be appreciated.

Thanks in advance

Baz