BMW 335i Twin Turbo Test Drive and Walkaround from Chicago Cars Direct
Video Presentation and Walk Around of the 2007 BMW 335i Sport Sedan with
Chris Moran of Chicago Cars Direct.
The data doesn't make any sense. We're tearing our collective hair out
trying to determine why the track-test numbers from our 2007 BMW 335i test
car are so far off.
Our freshly minted 3 Series twin-turbo
coupe has not only eclipsed BMW's own impressive performance figures — by
a ton — it's also smoked those of the 2005 BMW M3 Competition Package, a
car we called "The Best M3 Ever Sold in America." And while that admittedly
turbo-deprived car had been a six-speed
manual, the Arctic Metallic 2007 BMW 335i Coupe cooling in the driveway is
but an automatic. Nothing about our Austrian First Drive of the car
prepared us for this.
More than half fast
Consider the facts: This 2007 BMW 335i test car blazed from zero to 60 in
4.8 seconds. BMW says the new coupe mit twin-turbo engine and Steptronic six-speed autobox
should make that trip in 5.5 seconds. Seven-tenths of a second quicker?
That's 13-percent better than BMW's claim. Folks give aftermarket tuners
wads of cash for that kind of performance bump, especially when a car
starts out in the mid 5s to begin with.
Our 335i similarly scalded the quarter-mile in 13.3 seconds at 105.9 mph.
For comparison, our 2005 M3 Competition Package used up 5.5 seconds getting
to 60 and finished the quarter-mile in 13.7 seconds at 105.4 mph — close,
but still a rearview-mirror performance. We almost beat the all-powerful
2007 Audi RS4, too. Despite a 120-horsepower advantage and
all-wheel-drive launch superiority, it just nicked our 335i's 0-60 and
quarter-mile times by a paltry 0.1 second each.
Something's up. Could BMW be soft-pedaling the output and performance
numbers to leave marketing headroom for a more outrageous 2008 M3 V8 to
come? Did the luck of the draw or some other means provide us with an
overachiever? We've gotta check into this.
There can be no doubt that BMW's new twin-turbo 3.0-liter straight-6 engine, complete with
direct injection and a high 10.2:1 compression ratio, is impressive. Two
smaller snails were assigned to only three cylinders each so they'd spin up
faster, reducing lag and
increasing torque at low engine speeds. Boy, does it work, as this beastie
is rated at 300 hp at 5,800 rpm and 300 pound-feet of torque spreading from
1,400-5,000 rpm. In a rear-drive coupe weighing in at 3,579 as-tested
pounds, that sounds about right — for 5.5-second 0-60 bursts, that is.
In order to see what she's really putting out, we've brought our 335i to
the chassis dynamometer at MD Automotive in Westminster, California. And
since chassis Dyno
figures are always lower than manufacturer ratings because the former
includes drivetrain losses and the latter does not, we've secured the help
of an alert reader who has volunteered his month-old 335i for comparison.
Steve Harrison's identically equipped 335i automatic is fresh off a trip up
the California coast and all broken in. We should be able to tell if our
press car's performance is unique or not.
After a short time, two sets of fresh numbers sit before us. Steve's car
produces 272 rear-wheel hp at 5,970 rpm. Considering drivetrain losses,
he's easily seeing the promised 300 horses at the flywheel, probably more.
Our test car produces a similar 273 at 5,970. But wait, there's more: While
Steve's motor gently tapers off as rpm exceeds six grand, our mill
continues to make more power until it tops out at 279 at 6,295 rpm, at
which point Steve's 335i lags 19 ponies behind. Notably, our car maintains
its advantage for the remainder of the rev range.
So what's up?
A comparison to BMW data shows that Steve has nothing to be worried about,
as his 335i's rear-wheel output curve looks about right when compared to
factory flywheel data. Our car is simply stronger in such a way that makes
our pavement-melting 4.8-second 0-60 more understandable. But why?
We're glad you asked. MD's Dyno can also measure turboBoost
during runs. It turns out that at any given rpm in the disputed region
between 5,000 and 6,500, our car consistently makes about 0.5 psi more Boost. Subtle, but a little goes a long
way. Is this mere production variation? We can't dig deep enough to know
for sure. If anything, this exercise underscores the potential of
aftermarket chip tuning. Ain't electronically controlled turbo engines fun?
For the record, during a desert freeway assault to Vegas at an average
speed we don't care to print, the 335i achieved 25.9 mpg, compared to a
29-mpg EPA highway rating. With a lot of city and freeway stop-and-go
thrown in, the overall average drops to 20.3 — just above the 20-mpg EPA
city rating. With less lead in the shoes, the EPA figures actually seem