Why is airport car rental so cheap [closed]

It's impossible to give a definitive answer without (at least) knowing more details like dates/etc, but what you've described is not uncommon. A few of the common reasons for this are...

• Airport locations frequently have much more competition. Newcastle Airport has around 10 different rental companies, so competition will be much higher than an off-airport location which will potentially result in lower prices.

• Economy rental companies will often ONLY have on-airport locations. Even if you're not looking at renting from one of these companies, it again helps with competition.

• Rental companies often have far more cars than they have space to store. This isn't normally a problem as their cars are rented out, however during periods of low demand they may not have enough space to store their non-rented vehicles. In order to avoid this, they will sometimes reduce car prices to almost free in order to stimulate demand. This often occurs only for "quiet" days of the week (weekends at some locations, weekdays at others)

• Airports normally have additional taxes and fees, however there are sometimes charged as a percentage of the rate, so for cheap rentals sometimes only have a minimal impact on the price.

In particular for Newcastle Airport there appears to be one company that has particularly cheap rates. If you do an internet search for this company you'll find a number of reviews that paint an interesting picture of their business practices.

A car rental I got in Dublin had hidden in the fine print a note that there would be a €30 charge for airport pickup, payable at time of pickup (in addition to what was paid and contracted for online for the rental period). (I did notice, but it would have been very easy to miss). Which put that rental in approximately the same price range as others which did include any airport pickup fee.

I would be suspicious there's something like that going on.