Eric's Autos: 2018 VW Golf
They're fraternal twins, remember?
The major mechanical differences come further down the line. With the Golf, you can go manual (five-speed) or automatic (six-speed), whereas the A3 is not offered with a manual transmission but has two automated manuals -- and the option to go all-wheel drive without going to the wagon.
On the Road
The output of the Golf's turbocharged four-cylinder engine is comparable that of six-cylinder engines that are about 25 percent larger, and it produces peak torque almost as soon as you push the Start button, at just 1,600 rpm. So it accelerates as if it has a larger engine but lacks the flat spot or lag that was once characteristic of turbocharged engines. This has been accomplished via the use of smaller "sequential" turbos that build boost pressure almost immediately.
The VW is also fun to drive -- especially compared with its Audi twin -- because it can be ordered with a manual transmission. The Audi is technically quicker, and its available AWD gives it a traction advantage in the curves as well as in the snow -- but that's not the same thing as more fun.
At the Curb
The Golf and A3 are shaped differently -- the Golf being a stubbier and taller five-door hatchback and the A3 being a sleek and low sedan -- but the interior dimensions are nearly identical.
Well, some of them are.
Both cars have exactly the same 41.2 inches of legroom for the driver and front-seat passenger and nearly the same backseat legroom (35.6 inches for the VW and 35.4 inches for the Audi).
But the Golf, being a hatchback, has vastly more space for carrying things in addition to people: 22.8 cubic feet behind its second row and 52.7 cubic feet with the second row folded. You can also raise or lower the Golf's cargo floor almost 4 inches to adjust for various cargo shapes.