Our article analyzes the relationship between petrol prices and household expenditures on petrol using data from INSEE's Family Budget Survey. In the short run, on cross-sectional individual data, we estimate the price elasticity of fuel between -0.25 and -0.35, with wide differentials by living standards. The most affluent households do not respond significantly to petrol prices, unlike modest households. To estimate long-term price elasticities, we had to construct survey pseudo-panels from 1985 to 2006. We found values ranging from -0.6 to -0.7. For the most modest households, the values lie between -0.7 and -0.8. Their elasticity slightly exceeds that of the most affluent households (between -0.6 and -0.7), whose demand is more inelastic to fuel prices. Rural households display a lower elasticity (between -0.7 and -0.8) than urban households (between -0.8 and -0.9). These results indicate that not all households can adjust their consumption significantly in step with short-term price fluctuations. By contrast, long-term adjustment capacities are high for all sub-populations examined-on condition that the changes in consumption consecutive to price changes observed in the past can be reproduced.