(continued from above)
Not even two years after the debut of the current 5 Series this Series of performance/luxury
midsize automobiles undergoes a significant update for its 2006 model year. The
6-cylinder models - 525i and 530i Sedans, new all-wheel-drive 525xi and 530xi
Sedans, and a new 530xi Sports Wagon - are the first to make their debut, their
new model year beginning with March 2005 production. The V-8 model will enter
its '06 model year as of September production.
The 530xi abounds with rational design and thoughtful details which include a high-lift tailgate - almost 73 in. head clearance - with Soft Close feature. The tailgate is electrically released from the exterior or interior switch or the remote. The rear window may be opened separately, for convenient loading without opening the tailgate. A power opening and closing feature is included in the Premium Package. Wider than that in the previous Wagon, and with straight, essentially vertical sides, the cargo area offers 17.6 cu ft. of volume up to the tops of the upright rear seats and a maximum of 58.3 cu ft., rear seats folded, cargo loaded to ceiling. The cargo area includes a lockable storage space under the cargo floor, in a tray with adjustable dividers to help secure smaller objects.
All-New 6-Cylinder
Engines
These days, most 6-cylinder engines are V-6s. By contrast, BMW's "sixes" are
inline engines, noted not only for their layout, but also for exceptional
smoothness and unique sound. BMW customers and independent critics treasure them
for these attributes, and BMW has retained the inline-6 layout while developing
it toward reduced weight, more compact dimensions and even more brilliant
performance, smoothness and sound. Confirming all this, AutoWeek's February 28,
2006 issue noted (in the context of the new 3 Series) that the new engine
"sounds great, with an emphasis on clean mechanical noise from the engine bay
rather than the tone of the muffler." BMW's new generation of 6-cylinder engines
is designated N52.
Valvetronic variable valve lift. This patented innovation, already enhancing the
performance and fuel efficiency of BMW's V-8 and V-12 engines, now appears in a
BMW 6-cylinder engine as well - and in evolved form. Valvetronic varies valve
lift to a far greater degree than other variable-lift systems - so much, in
fact, that it replaces the traditional engine throttle. Engine breathing is
controlled entirely by the valves themselves.
Unique New Magnesium/Aluminum
Composite Engine Construction
With the N52 engine, BMW introduces a unique and pioneering engine structure:
magnesium/aluminum composite construction, the first in a contemporary
automobile. Structurally, the all-new engine block consists of three major
castings:
- Bedplate (magnesium alloy). This casting forms the lower portion of the block
(crankcase), and is similar in concept to a construction element found in some
racing engines - as well as the 500-hp V-10 engine powering the new BMW M5.
- Upper crankcase (magnesium alloy). Joining the bedplate at the level of the
crankshaft (main) bearings, this too is a weight-saving casting. Mounted onto
the bedplate from above; combines with the bedplate to form the cylinder block's
outer shell. The result is an ultra-rigid, yet remarkably light engine
structure.
- Insert (aluminum alloy). Forms the cylinders and their coolant passages.
Analogous to the entire blocks of BMW's V-8, V-10 and V-12 engines, silicon
particles are cast into this insert; a "soft honing" machine removes just enough
of the aluminum to leave the crystals as ultra-hard cylinder surfaces.
The engine's camshaft cover is of weight-saving magnesium. The VANOS sprockets,
via which the camshaft chain drives the two variable-valve-timing mechanisms,
are newly of aluminum. And the chain camshaft drive - a high-durability,
low-maintenance feature of all current BMW engines - has an aluminum chain
tensioner that also saves weight.
BMW 530xi Sports Wagon: Review (2/2)
