Continental A.G. calls it the ``eco balance.'' Groupe Michelin refers to the ``total energy balance sheet.''
Goodyear simply talks about reduced tailpipe emissions.
Of the various ways the tire industry can influence energy consumption, reducing rolling resistance has the greatest effect, manufacturers agree.
Michelin estimates replacing current-generation passenger car tires with ``green''-as in environmentally friendly-tires would reduce the annual fuel consumption in the European Union countries by 5 percent, or 1.6 billion gallons of fuel.
While purely theoretical and highly dependent upon motorists' maintaining proper inflation, the calculation reveals the potential of tire design.
Reducing the weight of the average tire by 5 percent-a development most of the major tire makers already have accomplished in the past few years-saves another 32 million gallons of crude oil. Increasing the tread life of a tire 10 percent on average would save 86 million gallons of crude oil annually in the EU, the firms say.
Increasing the instance of retreading throughout the EU to 20 percent from its current 12-14 percent level would yield a further savings of 45 million gallons up front.
Depending upon the quality of retreading and the age of the casing, however, these savings could be offset by higher rolling resistance of the retread vs. fitment of a new, ``green'' tire, Continental argues, thereby calling into question the entire passenger car retread industry's existence.