Odometer on my compact: just turned 200,000
Advertised gas pump price: C$0.899 / liter
Cost of filling up my car: C$35
NYMX crude, Apr 1, 2005: $55.71 / barrel
Crude, 1980, in 2005 prices: $90 / barrel
GDP spent on gasoline, 2004: 2.1%
GDP spent on gasoline, 1980-81: 4.5%
GDP spent on gasoline, for Goldman Sachs $50-105 crude prediction: 3.6%
US gas prices in that scenario: $4 / gallon

Goldman Sachs made some news and drove up oil prices by predicting a $50-105 trading range for oil for the next few years, essentially saying that current prices are low. And they are, historically, inflation adjusted. The analyst is saying that if oil prices are going to be constrained by demand (i.e. no sudden new supply appearing), this is where they will need to go before Americans in the aggregate start to conserve. They've done it before, they can do it again, but it will make current prices look cheap.

Goldman, however, the world's largest energy trader, is no doubt long oil, so take their public pronouncements with a grain of salt.

Updated: calculated a gasoline %GDP from here, which gives 2004 GDP as 11,735B, "gasoline, fuel oil, and other energy goods" as 244.9B. That'll include diesel burned either in transportation or heating, but not "electricity and gas", which is a separate item. Another interesting tidbit: MSFT wrote a special dividend in 2004Q4. This dividend is large enough to affect the national accounts!