Originally Posted by TheMuffinMan
Not significantly. Water boils at 95°C instead of 100°C here, so only a 5% drop.
Petrol/gasoline has a wide temperature range at which it boils and if it's a winter fuel, will boil at lower temperatures. At sea level a reasonable assumption would be 95°C. Octane, butanes and isobutanes, ethanol content all have an impact on the temp at which it boils too. At 1,800m, this will be lower at around 90°C; but possibly even lower.