Once upon a time there was a group of guys standing around a 1999 Cadillac Eldorado with a plan to move its front engine and transmission to the rear of the car to make it a mid-engine GT. Then, just by chance one of them casually suggested that they could put a second engine in the rear and create a two engine GT. This is what they did, and the result was the Mosler Eldorado TwinStar sports GT – a twin V8 GT.
Fast Facts
- The Mosler Eldorado TwinStar started out as a standard 1999 Cadillac Eldorado.
- The Cadillac Eldorado was equipped with a front mounted GM NorthStar DOHC VVT V8 engine driving the front wheels via a four speed automatic transmission.
- The team at Mosler Automotive decided to turn that conventional Eldorado into a twin engine luxury high performance car by installing a second GM NorthStar V8 in the rear of the car making it a front-engine plus rear-mid-engine 600hp piece of automotive excitement.
- Only five of these Mosler Eldorado TwinStars were made: but they rank as one of the most interesting cars to emerge from the beginning of the twenty-first century.
A car with two engines is not a new idea, but twin-engine cars are without doubt unusual, if not rare.
Citroen created a twin-engine version of their utilitarian 2CV which they called the “Sahara”.
The Sahara was made to be an all-wheel-drive “go anywhere” type of vehicle and it seems to have been quite successful in that role. They were cars that got a lot of use in rough conditions and as a consequence very few have survived to make it onto the collector market.
Putting two engines in a car provides some advantages, and some significant disadvantages. A twin engine automobile can be made to have all-wheel-drive with the handling advantages that provides: and having an engine up front driving the front wheels and another one in the back driving the rear wheels provides excellent weight balance front to rear.
The disadvantages are significant however: you have two engines and transmissions to maintain: and two engines to feed fuel into. There is also the challenge of balancing the power delivery between the front and rear engines.
All these issues can be problem solved, so the most pertinent question comes down to one of value – is it worth it?
For the Citroen 2CV Sahara it was worth it. But for the twin-engine version of the Cadillac Eldorado it may or may not have been depending on your interests and priorities, as evidenced by the fact that only five were made and sold.
The twin-engine Cadillac Eldorado was not the brainchild of the design engineers at General Motors, although they designed and built the original conventional front-wheel-drive car on which it was based: it was the creation of a small performance car workshop, Mosler Automotive.
The founder of Mosler Automotive was Warren Mosler, who was an economist and co-founder of the Center for Full Employment and Price Stability at the University of Missouri-Kansas City.
He was also a performance car enthusiast who loved the creativity inherent in performance car creation, in fact he was so motivated that he started Mosler Automotive in 1985, at that time calling it Consulier Industries.
The first production car was the Consulier GTP which was a mid-engine sports car equipped with a turbocharged Chrysler 2.2 liter engine ensconced in a fiberglass and foam monocoque chassis. This car was subsequently re-named the Mosler Intruder/Raptor when the automotive division of Consulier was separated out on its own as Mosler Automotive in 1993.
The Mosler Intruder was a re-styled and technically improved version of the Consulier GTP, fitted with a 300hp GM LT1 engine and was so successful in competition during 1993-1994 it was banned: which was probably a tad annoying for Warren Mosler and his team.
It was during that time that Warren Mosler and his team got to thinking about creating a luxury all American mid-engine GT car and rather than start from scratch they decided to use an existing luxury car that was not a mid-engine GT as the foundation for their new model.
The car they chose as the basis for their new car was the Cadillac Eldorado with the plan to remove the front-engine front-wheel-drive and re-locate the engine and drive to the middle of the car.
It was during this concept and design process that someone casually suggested that instead of moving the front engine to the rear they could just add a second engine, instantly creating an all-wheel-drive grand touring car delivering around 600hp, as opposed to a mid-engine GT delivering a paltry 300hp.
In a typical “boys will be boys” moment heads nodded and it seems this was deemed to be a rather good idea, and one that was not going to be excessively difficult to achieve.
A Cadillac Eldorado was obtained, a new rear sub-frame was created into which to ensconce a second Cadillac NorthStar V8 engine and transmission, new rear-end bodywork was fabricated, and lo and behold the Mosler Eldorado TwinStar was born.
The production conventional single-engine Eldorado was of itself a sophisticated automobile and the NorthStar engine was a sophisticated power unit.
The standard 1999 Eldorado featured adaptive continuously variable road sensing suspension, traction control, electronic stability control along with climate control and automatic windshield wipers, all integrated into a luxury interior with a nice sound system for those long trips along the highway.
So this was a very nice base car into which to add a second NorthStar engine.
The NorthStar V8 was a 4.6 liter four-valves-per-cylinder DOHC VVT (Variable Valve Timing) engine with alloy block and heads. It was a complex design and in the 1999 Cadillac Eldorado ESC (Eldorado Sports Coupe) developed 275hp @ 5,600rpm, while in the more luxurious Eldorado ETC (Eldorado Touring Coupe) the engine was the 300hp @ 6,000rpm version. The torque from these engines was 300lb/ft for the 275hp version and 295lb/ft for the 300hp.
Fuel tank capacity was 19 US gallons for the ESC or 20 US gallons for the ETC version.
Fuel economy for the standard single-engine car was 15mpg city, 24mph country, 18mpg combined.
Standing to 60mph was accomplished in a tad below 7.5 seconds.
The transmission was a four-speed automatic.
The Mosler TwinStar retained the original four seat passenger compartment of the standard Eldorado, but of course the trunk/boot in the rear became full of lovely NorthStar V8 engine – so the resulting car could accommodate four people with no luggage, or two people with their luggage on the back seat. So the car was a practical daily-driver road car given those limitations – probably more practical than many mid-engine GT’s.
Having twin NorthStar V8 engines the combined power of these engines was 575hp for the early cars made, which used a 275hp engine in the front and 300hp engine in the rear.
Fitting this second engine required the wheelbase to be lengthened and fitting of cooling ducts on both sides to feed air into the rear engine’s radiators.
Effectively doubling the car’s power and torque had a significant effect on the car’s performance as one would expect with the standing to 60mph for the twin-engine car being pruned down to around 5 seconds and top speed said to be up around 200mph although the production car’s had a speed limiter set to 126mph.
The addition of the second gas guzzling V8 had the predictable effect on the car’s fuel economy which was said to have been around 10mpg (US).
The car’s handling was good. It was well balanced and boasted all-wheel-drive to distribute its power to the wheels in an efficient way.
The Mosler Cadillac Eldorado TwinStar most certainly appeals to my “boys will be boys” penchant for things novel and technically advanced – not to mention the provision of around 600hp from over 9 liters of engine capacity – even though that would provide a wallet emptying experience at the gas station.
Each engine was started separately and the sheer sound of those sixteen cylinders burbling into life would be a rather nice beginning to any journey.
Only five Mosler Cadillac Eldorado TwinStars found customers who were willing to shell out the shekels to own one. One of these was the late Clarence Clemons, sax player of Bruce Springsteen’s E Street Band and a man who appreciated music – including the music of the twin V8 engines working in un-synchronized gorgeousness.
Fabulous and unconventional ideas typically don’t get the praise and acceptance they deserve – and that was to be the fate of the Mosler Cadillac Eldorado TwinStar – fascinating, fabulous, but ill-fated.
Mosler Automotive went on for a season making high performance cars of a more conventional design, and also did designs for some practical road vehicles including smaller communter cars, electric cars, and composite body cargo vans.
Mosler Automotive was taken over by Rossion Automotive in June 2013.
You can find the current Mosler Automotive web site if you click here.
You can see and hear this car at Doug’s Cars on YouTube if you click here.
Picture Credits: Feature image at the head of this post courtesy RM Sotheby’s. All other pictures as individually credited.
Jon Branch is the founder and senior editor of Revivaler and has written a significant number of articles for various publications including official Buying Guides for eBay, classic car articles for Hagerty, magazine articles for both the Australian Shooters Journal and the Australian Shooter, and he’s a long time contributor to Silodrome.
Jon has done radio, television, magazine and newspaper interviews on various issues, and has traveled extensively, having lived in Britain, Australia, China and Hong Kong. His travels have taken him to Indonesia, Israel, Italy, Japan and a number of other countries. He has studied the Japanese sword arts and has a long history of involvement in the shooting sports, which has included authoring submissions to government on various firearms related issues and assisting in the design and establishment of shooting ranges.
