by Natalie Paris from The Telegraph, September 6, 2017
Budget carriers are expanding their networks to fly passengers further than ever before, but do they always offer the cheapest fares?
In short, no. New routes to long-haul destinations, including San Francisco and New York, for example, hit the headlines recently with their low lead-in prices, but with air fares constantly changing, the most attractive tickets can be hard to track down on the dates required.
Which airlines, then, offered the cheapest return fares to popular destinations, on average, in 2016?
Research conducted by the flight comparison site Skyscanner for Telegraph Travel and Which? Magazine, found that low-cost airlines really are challenging traditional long-haul carriers on price - just not to every destination.
We took 20 popular routes where budget carriers are attempting to undercut their rivals and took an average of the fare price for a return journey across the whole of last year, based on search results supplied by Skyscanner.
The routes were a mix of services starting in either London or Edinburgh.
The results showed that the biggest average saving travellers could have made was £252 on a flight from London to Mauritius, flying with Thomson Airways. The average price for this route was £762 in 2016, but Thomson sold return fares for an average of £510.
In fact Thomson, according to Skyscanner figures, was the provider of the cheapest flights to a number of key winter sun destinations.
A savvy traveller could fly to Cancun with Thomson and tour the more unspoilt parts of the Yucatan from there
Its flights to Cancun and Jamaica were also priced well below the average airline fare, with a return flight with Thomson from London to Cancun costing an average of £151 less, while one from London to Jamaica, cost £179 less.
It may not be the first airline you would think of going to when booking a long-haul trip, but "go further, pay less" is one of Thomson's advertising messages and its website currently offers deals on flights to beach destinations including Goa in India, Phuket in Thailand, and Phu Quoc in Vietnam.
Flying to San Francisco with WOW air might have saved you a sizeable sum last year, the results showed, with a WOW fare (£528 return) costing £185 less than the average fare in 2016 (£713 return) on the London to San Francisco route.
New York has been something of a battleground of late for airlines competing to offer the cheapest return seats from the UK. However, it turns out that American airline Delta fought off international competition over the course of the year to provide the cheapest average return fare (£409, compared to an average overall fare of £457).
Yet British Airways is apparently more concerned about beating the prices Norwegian Air offers to New York. To bring down its fares it will begin flying reconfigured Boeing 777s that hold an extra seat per row from Gatwick to New York next summer.
Travellers looking to visit Delhi soon should note that Turkish Airlines offered the cheapest average price for a return in 2016 of £383, compared to £497.
Budget travellers in the UK could soon have another low-cost option for trips to Delhi at their disposal, however. Scoot is looking to start flights from Manchester to Delhi and Mumbai for around £310 next year . Meanwhile, SpiceJet and IndiGo, India's two biggest no-frills airlines, are reportedly planning direct routes to Gatwick.
When travelling to Singapore, Air China had the most affordable fares in 2016. But its average economy seat price of £427 could well be undercut further in the next month, as Norwegian is launching a new route between Gatwick and Singapore with fares that it says will start at £360.
In Europe, Ryanair and Norwegian provided the cheapest return flights, on average, to many of Telegraph readers' favourite cities.
Ryanair was revealed as offering the lowest average return fares to Berlin, Madrid and Rome, while Norwegian was cheapest to Barcelona and Reykjavik.
Surprisingly, the lowest prices on average for a return to Paris came from Transavia, a little-known budget Dutch airline.