Which would be the best rental car for driving the Alps this summer? VW Polo, VW Golf, Ford Focus or Ford Fiesta? 2 are Economy and 2 are in Compact category.

How many people, how many pieces of luggage?

You are wise to ask this question! We had one rental car last year in Provence that was more than adequate for the perched villages, however for the hill towns of Tuscany we were given a very sub par vehicle - it had poor power. That being said - I don't know the answer to your question...but it's a good one!!!

It's difficult to answer because even those cars you mention come with a variety of engines, from low-powered 1 litre to beefy 2 litre turbo. Usually economy cars are 3 doors rather than 5, and have smaller engines and often no air-conditioning. In terms of size, Polo is the smallest, followed by Fiesta, Golf and Focus. The first two are adequate for two people, possibly three, while Golf is ok for four and Focus can accommodate 5. Also it has the largest trunk space of the lot.

You might be offered a larger car at the desk with no extra charge and you should say, No Thanks. While power is important, a tight turning radius is too.

It is not much fun driving a poorly powered economy car in the Alps.

I would rent a compact car - the price difference should be marginal.

Golf and Fiesta sound best.

If you can choose at the rental desk, go for a 1.8-2.0 liter turbo diesel with decent HP if available. Much more traction at lower RPM than their equivalents with petrol engines.

Larger cars are not necessarily fun on winding mountain roads.

2 adults 2 pieces of luggage.

I'd opt for the VW Golf. Cool car. Easy handling. German quality.

On our last visit I think our hire car was a small engined Fiesta which nevertheless coped well with the steep roads we were using. I'd rather risk having something underpowered than give in to the temptation of a cheap upgrade - in the Alps, small is definitely beautiful!

Another thought, if a sat nav's available it not only makes navigating easier, but it also shows the way the road bends ahead - especially useful at night.

I second getting the turbo diesel. The turbo eliminates any performance loss do to altitude.