But if you took them out for 1000 miles of hard driving through Arizona and southern California, as we did, running along Interstates, winding deserted desert highways, twisty mountain roads and a good measure of urban traffic--as well as the super-tight road course at Firebird International Raceway near Phoenix--you would find what we found: Rarely have two such similar-on-paper cars been so different in personality.
The BMW 325e is essentially the 318i (R&T, July 1983) with the 2693-cc inline-6 engine
from the 528e. The e stands for eta, the Greek letter for efficiency in
engineering parlance, and this powerplant is designed to provide high torque at low rpm to
enhance fuel efficiency. In the 325e, there are some minor modifications to the
digital electronics and the oxygen sensor is in a different place, but essentially it's the
same engine. Output is 121 bhp at 4250 rpm and 170 lb-ft torque at 3250.
The Maserati engine for the U.S. is a 90-degree V-6 displacing 2.5 liters, instead of the 2.0-liter European engine in the first Biturbo we drove (May 1983). There are twin IHI turbochargers, a single cam per cylinder bank, with the block and heads of aluminum. It's rated at 185 bhp at 5500 rpm, with torque given as 208 lb-ft at 3000.
The difference in driving characteristics of these two engines is phenomenal. The BMW has an abundance of torque at amost any engine speed, but it is a flat torque curve that encourages the driver to shift gears well below the 5000-rpm redline. The Maserati V-6, however, has that typically Italian zip, which means not much initial torque for getting off the line, but, boy, does it love to rev right up to (and through) the 6200-rpm limit. And they both have distinctive songs to sing: the Maserati engine presents all the soaring trills of a Verdi opera, the BMW's sound is like a Gregorian chant.
It should come as no great surprise, then, that the Bimmer will accelerate briskly away
from the Biturbo for the first 300 ft. but then the Italian car's turbos get to work (at
2500-3000 rpm) and the Maserati sails on by, reaching 60 mph in 7.2 seconds, while the BMW
takes 8.9. Once in the lead, the Maserati never surrenders its advantage. It
roars through the quarter mile in 15.7 sec at 88.0 mph while the BMW needs 16.6 sec at a
speed of 81.5, also quick but behind for the rest of the run.
Driveability, on the other hand, is the province of the Bimmer. It has the advantage of electronic fuel injection versus the Biturbo's Weber carburetor and manual choke arrangement. The difference is that the 325e engine runs smoothly at any speed, while the Maserati has an occasional display of temperament: rough idle and a bit of stumbling on initial throttle input and under heavy, high-rev loads.
In real-world driving conditions, the BMW proves itself a willing performer with great engine flexibility. Power is always only a jab of the right foot away, and the driver accustomed to high-torque American V-8 engines will find the eta's driving characteristics much to his liking. With the Maserati, the extra punch to pass slower traffic calls for a downshift of at least one and often two gears, a slight hesitation for turbo lag, and then, hang on baby.
It's a shame taht the BMW's engine doesn't call for greater use of the gearbox, because its 5-speed is the better of the two. It has the traditional BMW precision and snick-snick shift action, along with the more common 1-4 H-pattern with 5th to the right and forward. The Biturbo transmission has 1st gear to the left and back and the remaining four gears in the H. It takes some getting used to, which comes with time, but the gear slots lack definition. In hurrying along a twisty road that requires lots of upshifting and downshifting, the Maserati's gear lever can leave you wondering if you really have the gear you want for that sharp downhill curve ahead. Both gearboxes have a problem with cold-weather sluggishness: neither likes anything more than a gentle, slow hand until warm.
The BMW 325e is 300 lb heavier than its 318i little brother and as a result its spring and shock rates are stiffer to handle the extra weight. BMW moved the battery to the trunk of the car and uses a heavier rear axle to cope with the 6-cylinder's greater torque, so front/rear weight distribution (without driver) is 54/46 for the 325e compared to 55/45 for the 318. To balance front rear roll stiffness, the Munich engineers have added a rear anti-roll bar to the 325 where the 318 had none. The 325e is set up to understeer under heavy throttle, and it does, but we found some disconcerting trailing-throttle oversteer when hustling along winding roads and at Firebird Raceway. BMW says acceleration/deceleration load transfer distribution is very similar for the 325 and 318, but that the 6-cylinder engine has appreciably greater compression braking which may help account for the oversteer when the driver lifts off the throttle in a corner. And, of course, this oversteer gets worse if you jump on the brakes at the same time.
Both the BMW and the Maserati Biturbo feel sports car-like in their handling up to about
7/10ths. They are sure-footed and will take twists and turns in their respective
strides, with the Bimmer exhibiting considerably more body roll. Beyond that brisk pace,
though, when you really start to crank them on, the BMW's rear end starts to lose its grip
and get twitchy. The Maserati has higher limits, but eventually it, too, will lose
rear adhesion and when it lets go it's somewhat more serious because of the higher speeds
involved. Also, the Maserati's steering is markedly slower than the Bimmer's, so it's
not as easy to catch the rear end breakaway and get the car back on teh proper line.
In performing our slalom test, for example, the Engineering Editor managed a little off-track
excursion in probing the Biturbo's ultimate limits.
One of the striking differences between these two sports sedans is their accomodations. The BMW has all the high-tech starkness and businesslike interior design of a laboratory, while the Maserati interior looks and feels like a cozy den. Both our test models had leather seats (optional on the BMW at $790), but the German seats are highly contoured and fitted with side bolstering that inhibits ingress/egress. And they can be decidedly uncomfortable if you're too large to fit. The Maserati seats are softer and more comfortable, and still provide adequate lateral support. The seat cushion, though, has some unusual bostering that can be obtrusive after long periods of time.
While the BMW's interior isn't nearly as inviting as the Biturbo's, the quality of materials and the level of fit and finish are higher. It's the difference of a handcrafted and thus imperfect environment versus a thoroughly complete, if machine-made interior. The BMW is capable, the Maserati is a cosmetic wonder, but the Italian car's pizazz inside is done with some shortcuts, such as the wood-grain looking panels and gearshift knob that are really plastic. And one note that mars all of the warmth and luxury of being ensconced within the Maserati is the noise level--road and wind noise at cruising speeds are tiresomely obtrusive.
If you are a driving enthusiast who loves cars, hungers for something exotic in the mid-$20,000 price range and have a strong streak of automotive romance in your makeup, the Maserati is the car for you. It has a strong dashe of joie de vivre in its driving characteristics, sensuous though understated styling and a beckoning interior. In short, it's the sort of car that makes you glad your hobby is cars rather than bowling.
On the other hand, if you worry more about reliability, parts and service availability and fuel efficiency, you'll be happier with the BMW 325e. It may lack the spirit and come-hither sexuality of the Maserati, but it does offer German precision and quality of engineering, along with status and a popular image. The 325e, like the 528e before it, opens new markets for BMW among buyers accustomed to American cars with high-torque V-8 engines. It is a car suited to the driving conditions most often encountered by American drivers. It doesn't hew to our admittedly narrow definition of an enthusiast's car, but its buyers will love it. If you're the person who chooses a car based on sensibilities rather than senses, the BMW is right for you.
For us, the choice is easy--we'll take romance.