The Mosler TwinStar Cadillac was pure double-engine Eldorado insanity

One of Cadillac’s most stunning achievements in its history was its impressive V-16 engine. This almost mythical mill was the product of a one-upmanship battle against bitter rival Packard’s V-12, when the Cadillac Series 452 model first went on sale in 1930. Long-term it has become a salient example of a corporate giant flexing its engineering acumen, especially when considering the updated Series 90 that debuted just prior to World War II.

Since then, only three other production cars—the Cizeta-Moroder V16T, and of course the Bugatti Veyron and Chiron—have dared to tack on that many cylinders in the pursuit of performance.

However brave, there are also low-volume aftermarket efforts to build 16-cylinder behemoths. In fact, one such project was a rather valiant attempt to resurrect the majesty of Cadillac’s past by doubling up on Northstar engines—and doubling down on the sheer complexity required to execute such a complicated power play.

It’s called the Mosler TwinStar, and it’s pretty damn weird.

Party in the front, and uh, party in the back, too

Twin-engine cars are nothing new. They’ve been deployed as both attention-grabbing novelties and one-off racing specials for decades by car companies and tuning shops eager to show off their technical skills. Much rarer are vehicles that genuinely strive to utilize the “one up front, and one in the trunk” engine layout in a daily-driver package. That earnestness to make this crazy idea really work is a big part of what makes the Mosler effort unique.

If that name sounds familiar, it’s because Warren Mosler—the man behind Mosler Automotive— was no stranger to trying new things and slapping his name on them. From the mid-’80s onward, his company found success selling a lightweight mid-engine semi-supercar, the Consulier GTP, powered by Chrysler’s 2.2-liter turbo-four engine. It was eventually banned by IMSA in 1991 when it proved nigh-unstoppable on the podium. Mosler would eventually follow the Consulier with the Intruder and the MT900, which hewed to the same general approach in terms of performance.

Mosler became interested in the Cadillac Eldorado, after it appeared in the early ’90s, as a foundation for a potential mid-engine hot rod. Why the Eldorado? Part of it was because of the theoretical ease with which its front-wheel drive Northstar V-8 drivetrain could migrate to the vehicle’s hindquarters. In an interview with Street Muscle Magazine, Jo Borras (an engineer who worked at Mosler) claims that an off-hand comment made by one of Warren’s visiting golf buddies that a twin-engine car would be “cool” convinced Mosler to change tack. Midway through the mid-engine Northstar Eldorado project, he made the radical choice to leave the original engine in place and just add a second Northstar. All of which was a perfectly reasonable thing to do.

The resulting 2000 Mosler TwinStar, as it became known, thus became the most recent road-going Cadillac to offer a 16-cylinder setup. Of course, it’s one that was far more unusual than anything GM could have conceived so many decades before.

Not quite a kludge, but…

Maybe you’re suspicious that a twin-engine Cadillac sold in the year 2000 but based off of totally-rad ’90s technology might be more than a little finicky out on the road. That’s not far from the truth, and as you might expect, complexity is to blame. 

For starters, the TwinStar doesn’t even use the same version of the Northstar engine at each end of the car, instead sticking with the base Eldorado’s 275-hp tune up front and making use of the ETC trim’s 300-hp unit at the back. Oh, and aside from shared throttle linkage, these engines operate completely independently of each other. That design therefore necessitates a pair of transmissions that shift at entirely different times, with the rear engine occasionally outpacing the front to the point where the base motor’s ECU defaults to limp mode after bashing its head against the rev limiter too many times. Fun! There are also two ignition switches, two gauge clusters with independent instruments to monitor each motor (with one mounted on the passenger dashboard), and double the fuel consumption, which works out to a healthy 10 miles per gallon in daily driving.

Then, of course, there’s the look. In order to make the new rear subframe fit properly, the Eldorado’s wheelbase had to be stretched several inches, and its flared fenders give it proportions that could best be described as “curious.” Adding to the car’s unusual sheet metal are the large air ducts just ahead of the rear axle, which were necessary to feed Northstar number two’s cooling system, matched by vents on the trunk designed to keep the entire enterprise from self-immolating.

Double-headed hooning

With 575 total horsepower on tap, the TwinStar was definitely quick, scorching the sprint to 60 mph in 5.0 seconds and running through the quarter in 13.4 seconds at 108 mph, according to a contemporary road test by Car and Driver. Those are BMW M5-level numbers for the early 2000s era, and nearly 2.5 seconds quicker than what a stock Eldorado could manage with its plain-Jane single-engine design. Handling was also excellent, and while the Eldorado was never known for its cornering chops, there’s nothing about the TwinStar that will get you into trouble on a twisty road, either.

Mosler only built five Twinstar Eldorados, with three of those going to a single customer who, according to Borras, was more concerned with whether he’d be able to escape should the front radiator be pierced by gunfire than the overall performance boost afforded by the conversion. The company charged $30K to add a second Northstar to your donor Cadillac coupe, which if you include the cost of the original car made the purchase price roughly $70,000 at the turn of the millennium.

Today, the Mosler TwinStar is an oddity that occasionally pops up on auction sites and on dealership websites with prices hovering around the $40,000 mark. The most recent offered was owned by the late Clarence Clemmons, sax-man extraordinaire for Bruce Springsteen’s E Street Band, and definitely a man who possessed the kind of lung capacity required to appreciate a deep-breathing, 9.1-liter drivetrain. 

Considering the six-figure sum it would cost to get behind the wheel of an original Cadillac V-16, such a modest sum for a piece of oddball automotive could be considered a deal… of sorts. No doubt the V-16’s precision engineering is more robust, but have you considered which you’d rather own for your next gunfight?