I realise I might be opening a can of worms but here goes. I may have to commute 300km 3 days a week (900 total) and I'm looking to buy a petrol car (as that's what is available where I am) that is fuel efficient at 140km/h.
140 is the speed limit here, and it can be dangerous (and annoying) to go slower... if you've driven in the Middle East you'll know what I mean.
I'm open to tuning the right car to find the right balance, but any tips of where to start is appreciated.
To be clear, there are no diesel or hybrids on the market here, and a Tesla is too expensive for me.
About 260km of the journey will be done at 120-140km/h.
I would have thought that with the price of petrol in UAE that economy would not really be an issue. Get a car with low drag (estates are supposed to be good). Keep the tyre pressures up a bit above the manufacturer's recommendations and use a light throttle (don't be in too great a rush to get to 140kph).
I have been driving in Dubai for 10+ years and I exactly know what you mean.
In all these years, I've driven various 4 cyl eco boxes (Elantra, Cruze, Civic etc) and while all these small cars were great for city driving, their puny little engines rev up too high at 130-140 km/h to return decent efficiency (especially with AC on blast).
I have had good to excellent results with bigger cars with bigger engines, heres some of my top picks based off my own experience:
Audi/VW 2.0 TFSI (Auto) - (Most german cars are geared for high speed autobahn cruising).
BMW 230i/330i/430i (8 Spd Auto)
Honda Accord V6 (6 Spd Auto) - ('13-'14 is a good choice if you are on a budget).
Toyota Avalon V6 (6 Spd Auto)
Ford Explorer V6 - (If you need a bigger vehicle).
Go to A car with bigger engines like V6 or V8 that are pared with the the CVT or those transmissions whose Final drive ratio is low. So that if you are cruising on 140KMPh the RPM will remain Low and provides your better fuel economy.