Go to a website called "Honest John",
then look for MPG,
There you'll find MPG figures submitted by real owners and not the manufacturers figures.
Probably not much, but without knowing what cars you're talking about it's impossible to say.
Depends on how much mileage you do, diesel is far more economical if you do a lot mileage.
If diesel fuel is more expensive in your area then it's a no-brainer - buy the petrol-engined car. If the fuels are about the same price but you don't drive huge mileages each year, then buy the petrol-engined car because it will take you years to recoup the higher purchase price and maintenance costs of the diesel vehicle. If diesel fuel is cheaper than petrol AND you drive more than 20,000 miles / 32,000 km each year AND you plan to keep the car for many years, then the diesel version should last longer and save you money in the long run. If most of your driving is in slow suburban traffic (rather than open-road), then a petrol-electric hybrid might be the best choice.
You have not even bothered to say what the cars are. Could be big or no differences or anywhere in between depending on that
your best of with the diesel . the petrol engine with auto transmission will guzzle the fuel more than a standard stick shift transmission.
Age and model is a big factor, modern petrol engines are much more efficient. Modern decent auto boxes are more efficient than the manual.
Imposable to say without knowing the cars you are referring to.
