I have diesels for the good mpg but rightly or wrongly I think diesels last longer.

It depends upon what design and make of diesel engine you have, as well as how it's used and how well it's maintained. Petrol enegines these days tend to be more hardy in comparison because they can tollerate a wider range of driving patterns. Common-rail turbo-diesels less so, however if they are used as originally intended, then there's no reason why they shouldn't last as long or longer.

Older designed diesel engines from the late 90s to 200s likle VAG's 1.9 are much less complicated on the emissions reduction front (maongst other things) and have been shown to go on and on if well maintained.

Even ones with a poor rep for reliability like the Mazda 2.2TD can go on and on without a problem if used predominantly for longer trips, serviiced properly and (hopefully) the few active DPF regens that take place are allowed to finish whilst the vehicle is in operation.

Diesels used to be the preferred choice of mini cab drivers but that's changed significantly now. Not only have they been affected by DPF problems but hybrid cars have been seen to have pretty resilient engines, and are often more economical.

Proper hybrids (not 'mild' ones) are well suited to urban driving, especially as they bare also automatics, which probably makes driving them that much easier in heavy traffic - much less stressful for the taxi driver.

That cars are no longer allowed to idle in certain urban locations for pollution reasons also means hyrbids and PHEVs / full EVs have a big advantage in the urban setting, especially big cities.

Whilst DPFs have improved in terms of effectiveness, they are still far more geared towards longer distance driving, which is probably why the airport / extra-urban taxi drivers still often use diesels.

Round my way (small town in a rural area), most minicabs are still mid-sized diesels. I suspect though that the current relatively large disparity in prices in favour of petrol means that the mpg advantage over diesel has been negated, never mind hybrids. Pointless though a minicab driver changing car types unless they have to for the reasons above or its at the end of its viable life.

Near where I live in West Yorkshire the price of diesel seems to be generally at a maximum of 179.9 p/l.

However there is one filling station on the A658 Harrogate to Leeds/Bradford airport road which is still charging 188.9. There must be a lot of people who just fill up without looking at the price.

Incidentally this station is charging 157.9 for unleaded so this gives a price differential of 31 pence, which is the largest I have seen.

Taxi business for drivers who've forgotten to fill up before the busiest trade period of the day?

I've seen some out-of-the-way filling stations charge exorbitant levels, just because they know some locals either can't be bothered to drive another 10 miles (or more) to the next nearest filling station and back (especially farmers) or the 'caught short' who would rather get fuel there than stray off their route and get lost and run out of fuel, especially in the dark / poor weather. Add 15p a litre onto whatever the regional average.

I wonder what the prices and differentials are at present at motorway services filling stations - they are normally well above most others, sometimes even those 'middle of nowhere' rural filling stations.