Switching over to the 545i and it's not only the double-hump profile of the centre dash that holds the instruments and navigation display that is different from the Audi. The quality of materials and build are not only less substantial than the A6 but also the last generation 5 Series. At least BMW didn't screw up the ergonomics. The relationship between the thick steering wheel, the aforementioned excellent driver's seat, gear shifter, and foot pedals, are all in place to make the act of driving easier. Where in the A6 you sit tall, in the 545i you can drop the seat down to Z4 levels and easily forget you are driving a mid-sized sedan. Like the excellent space utilization that BMW achieved with the bigger 7 Series, there's plenty of elbowroom when you start twirling the tiller with vigour.
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| (photo: John Leblanc, straight-six.com) |
If you've depleted your supplementary funds for the extra two cylinders these two cars enjoy over their lessor six-cylinder models, don't fret, its money better spent than any thrill an RRSP will give you. On paper, the 545i's larger displacing engine gives a 20 pound-foot of torque advantage over the Audi, but five less horsepower. The Audi's vee-eight is a detuned version of the 4.2 litre engine found in the smaller S4; it delivers 330 horsepower and 310 pound-feet of torque, increases of 30 and 15 over the last gen A6 4.2. Like its application in the S4, its NASCAR soundtrack is hard not to grin at. More refined and silkier than the old A6 4.2, it's smooth from idle to its 6,800-rpm limit. The only complaint is initial throttle tip-in that is abrupt as a grouchy maitre'd.
Standard in the new 2005 A6 4.2 is a six-speed Tiptronic automatic transmission that sends power to all four wheels through Audi's satisfyingly competent quattro system. In theory, Tiptronic hands over the controls to the driver. In practice, this sensitive tranny will still kick down if you accelerate hard. Not nice in a tight corner, or an onramp.
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| (photo: John Leblanc, straight-six.com) |
Lack of control of the drivetrain is simply not a concern with the BMW, as its standard six-speed transmission is a stick. Now, to be fair, we know that this is not a true apples-to-apples comparison. But Audi doesn't offer a manual in the A6 4.2, or their excellent Direct Shift sequential gearbox that we so enjoyed last year in their 3.2 TT coupe, but they do market Tiptronic as an equal to a manual transmission, so...
It also doesn't help the Audi's case that this BMW transmission's shift linkage is among the lightest and most friction-free in the car world. Whether in the 5 Series, Z4 or an X3, it's a sweetheart. Hooked up to one of the most sensuous, eager-to-please engines you can find and you'll rev the snot out of this drivetrain just because, well you can. The engine spins so easily, and compared to the Nextel Cup roar from the A6's mill, quietly. I readily found myself 1,000 rpm higher than what my ears and brains were telling me. Unlike the touchy Audi, throttle tip-in is progressive. Gear ratios have been matched to the BMW's vee-eight so well it's hard to screw-up the revs when changing cogs. It certainly smoothes out your driving skills and forgives any jerkiness on the driver's part. From the driver's seat, the 545i's drivetrain beats the A6--all-wheel-drive or not--hands and feet down.
