You can drive either type of engine'd car through reasonably dep water, as long as your speed, revs, etc are appropriate for the conditions.

Basically, if the water would be covering your feet (so 4" or so of depth), then you should be in as low a gear as possible, and at walking pace or slightly faster. If the depth is closing in on knee-deep, then you really shouldn't be proceeding, unless you really know what you're doing, and you know exactly where the air intake is, and at what height. There is, as tom says, a chance of damage to gearboxes, diffs, etc through breather pipes.

I've driven a Range Rover through 3 feet of water before now - basically, it was splashing over the bonnet. However, this was one of LR's own vehicles, and on their 'official' off-road route, with one of their staff in the passenger seat, telling me to carry on. I told him that if it went wrong, I was leaving through the sunroof !

Not something I'd be willing to do in my own vehicle though.

Most modern cars, including un-modified SUVs have their engine air intake so low they'd suck water into the engine which wrecks it when the crank tries to compress it.

SUVs which may go off-road sometimes have a "snorkel" intake fitted - but otherwise treat any wading depth specified in the handbook with utmost respect - and remember that speed creates a bow wave which increases the effective depth of the water.

Another factor to consider is that modern cars have doors which seal well enough to create flotation if the water is above a certain depth - this reduces weight/traction/grip on the wheels and if there's water flowing across can cause the car to go off the road - I wouldn't take a conventional car through water if I though it was more than 8" (200mm) deep.

IMO best advice is go a different way, floods are unpredictable as my mate found out, he went through a lane but didnt know the drain into the field had been washed away and lost the car in the field he was lucky to escape

He was in a Rover 1994 2.0 diesel, car was written off about 2 years ago

Anyone who goes through deep water may very well get through but all the low lying engine bits will be possibly soaked. Think starter motors and alternators. After a few weeks, their connections will start to corrode. As will earth joints to chassis rails.

That is a sure fire way to having lots of annoying electrical probles.

Any car with ECUs mounted on the floor is especially vulnerable - see VW.

Project C should ignore what his Dad says, it is foolish advice.

Driving through anything more than 3 inches of water is potentially dangerous for any car /driver unless extreme care is taken at very slow speed.

While attempting this , you will probably lose braking, you may aquaplane losing steering control, vital components may get waterlogged, electrical and mechanical eg, belts that drive power steering altenators etc lose their drive capability.

You no longer will be able to judge any hazards, potholes, obstacles under water.

And drawing water in through a low air intake could kill the engine stone dead, irregardless if petrol or diesel.

The thermal shock of cold water on hot engine components/exhausts etc might cause costly damage.

Your insurance company will be most reluctant to pay out if you intentionally drive through a flooded road and have an accident, most will refuse to pay out for a waterdamaged engine/electrics caused by intentional stupidity.