Thread: Fuel Economy vs Tyre Pressure

For a definitive discussion on tyre pressures and economy have a read of this page on Barry's Tire Tech. This is probably one of the best sources of information on the web regarding tyres. You might want to check the authors credentials before reading the article:

Barry's Tire Tech


Anyway to the article: Rolling Resistance and Fuel Economy

And a follow up posting re tyre size and rolling resistance.

Rolling Resistance and Fuel Economy (Continued):


I won't cut and paste as the whole article needs to be read, because the recommendations are a trade off.

The article is at least partly at odds with what I've said in the previous post, but I'm happy to defer to expert knowledge.

For a tech explanation of the load vs pressure ratio I mentioned above the following paper contains detailed but readable discussion and formulae. For my personal use I've put together a spreadsheet based on the formulae to calculate trye pressures based on axle loading.

http://dawsengineering.com/linked_fi...ducedloads.pdf

cheers
Paul

Thanks for the links, Offtrack.

What I found interesting is that whilst increasing tyre pressure from 24psi to 40psi reduces rolling resistance by 21%, for city cycle, rolling resistance is only 4% of total energy use, hence in total it reduces only 0.8%.

Thus for 15,000km/yr, 13L/100km, one uses 1950L which @ $1.50/L is $2925/yr. A reduction of 0.8% is only $23.40 per year. Not worth the loss of traction or decreased comfort in my view. Also insignificant cost of ownership of a landy.