Low tyre pressures will affect economy, how are you calculating the economy?
October, 31, 2012 AT 10:06 AM
Yes, they can. Rotational mass is about 10 times greater than dead weight. That means that every pound of dead weight is equal to ten pounds of rotating weight or close to it. It is not a super drastic change but it is visible. Do not expect a huge decrease overall, maybe a half to one mile per gallon depending on what you upgrade from and to.