---
title: "The Mosler Twinstar Was a Dual-Engine, 575-HP ’90s Super Cadillac"
description: "One V8 under the hood and another V8 in the trunk resulted in 9.1 liters of all-American displacement."
date: "2020-06-19"
modified: "2020-06-19"
authors:
  - name: "James Gilboy"
    job_title: "Contributing Writer"
    link: "https://www.thedrive.com/authors/james-gilboy"
url: "https://www.thedrive.com/news/34138/the-mosler-twinstar-was-a-dual-engine-575-hp-90s-super-cadillac"
categories:
  - "Cadillac News"
  - "Culture"
  - "History"
  - "News"
  - "News by Brand"
tags:
  - "Cadillac"
---

# The Mosler Twinstar Was a Dual-Engine, 575-HP ’90s Super Cadillac

![](<https://www.thedrive.com/wp-content/uploads/images-by-url-td/content/2020/06/35472565692_81aa59b7cd_6k.jpg>)
*\<em\>www.thedrive.com</em>*

Collapsing in 2013 due to the lack of sales, Mosler Automotive joined the ranks of many a defunct supercar manufacturer. Before it departed, however, it left us with more than a few cars to remember it by, such as the ugly-but fast Consulier GTP that was banned from [IMSA](<https://www.thedrive.com/accelerator/33504/imsa-will-return-to-real-racing-on-july-4-with-all-new-daytona-sprint-race>), and the supercar-fighting MT900. But then there is the 1999 Twinstar; a heavily-modified Cadillac Eldorado powered by—as its name implies—two Northstar V8 engines.

The Twinstar's origins reportedly lie in a misunderstanding between company founder Warren Mosler and one of his golfing pals, whom he had brought by the shop to show off a mockup of an upcoming, mid-engined performance car called the HP40 (short for high performance, 40 mpg). According to a [*Street Muscle*](<https://www.streetmusclemag.com/news/how-the-mosler-twinstar-cadillac-was-born-from-an-offhand-comment/>) interview with a former Mosler engineer, Mosler's guest proclaimed something along the lines of "[wow, cool, a twin-engined car](<https://www.thedrive.com/news/32626/wild-twin-engine-peugeot-205-gti-with-two-v-6-motors-can-be-yours-for-10000>)," an idea Mosler liked so much that he turned the HP40 into the Twinstar.

![message-editor%2F1592337879342-35472565692\_81aa59b7cd\_6kcopy.jpg](<https://www.thedrive.com/wp-content/uploads/content-b/message-editor/1592337879342-35472565692_81aa59b7cd_6kcopy.jpg>)
*Mosler's Twinstar brochure, *Mosler Automotive**

Twinstars' dual powertrains operated almost entirely independent of one another, with separate ignition circuits, ECUs, and individual four-speed automatic transmissions—no center differential or transfer case. The two powertrains were also apparently not of identical specification; the rear engine was slightly more powerful and had a higher redline, but shorter gearing, meaning the engines almost never shifted in tandem according to a 2000 [*Car and Driver*](<https://www.caranddriver.com/reviews/a15139961/mosler-twinstar-eldorado-specialty-file/>) test.

![message-editor%2F1592340814703-1544983\_369216249886757\_1131414015\_n.jpg](<https://www.thedrive.com/wp-content/uploads/content-b/message-editor/1592340814703-1544983_369216249886757_1131414015_n.jpg>)
*Mosler Twinstar's rear engine, *"King Daddy Caddy - Cadillac of the day." on Facebook**

What the two Northstars *did* share was a single accelerator that opened the throttle on 9.1 liters of octuple-cam American fury, specifically 575 horsepower and 595 pound-feet of torque. Despite weighing in at 4,780 pounds, these could rocket the Twinstar from zero to 60 in as little as a claimed 4.6 seconds, down the quarter-mile in 12.7, and to a limited top speed of 126 mph. The bulk and thirst of a second engine reportedly gave the Twinstar a pathetic 10 mpg, though it apparently didn't hurt handling. Reportedly, the Twinstar recorded 0.83 lateral G on a skidpad—on par with a current [Porsche Cayenne Turbo](<https://www.thedrive.com/news/34029/16k-will-either-get-you-a-nissan-versa-or-this-off-road-porsche-cayenne-turbo-build>) (as tested by [*Motortrend*](<https://www.motortrend.com/cars/porsche/cayenne/2019/2019-porsche-cayenne-turbo-first-test-review/>)).

![message-editor%2F1592340945311-one-of-five-1999-cadillac-eldorado-twinstar-by-mosler-for-sale-three-quarter.jpg](<https://www.thedrive.com/wp-content/uploads/content-b/message-editor/1592340945311-one-of-five-1999-cadillac-eldorado-twinstar-by-mosler-for-sale-three-quarter.jpg>)
*ebay via Bring A Trailer*

![message-editor%2F1592340921109-one-of-five-1999-cadillac-eldorado-twinstar-by-mosler-for-sale-rear-engine.jpg](<https://www.thedrive.com/wp-content/uploads/content-b/message-editor/1592340921109-one-of-five-1999-cadillac-eldorado-twinstar-by-mosler-for-sale-rear-engine.jpg>)
*ebay via Bring A Trailer*

![message-editor%2F1592340908101-one-of-five-1999-cadillac-eldorado-twinstar-by-mosler-for-sale-interior.jpg](<https://www.thedrive.com/wp-content/uploads/content-b/message-editor/1592340908101-one-of-five-1999-cadillac-eldorado-twinstar-by-mosler-for-sale-interior.jpg>)
*ebay via Bring A Trailer*

Because Mosler lengthened the rear end, the Twinstar still had back seats, which were as luxurious a place to sit as [1990s General Motors](<https://www.thedrive.com/news/33766/the-working-crt-touchscreen-in-this-4200-1990-oldsmobile-trofeo-is-worth-that-price-alone>) could imagine. It had a leather interior, a CD-compatible stereo, air conditioning, and power everything. What all this cost is the subject of dispute; the brochure above (circa 1998) touts a starting price as low as $64,500 in today's money, though *Car and Driver* reported the conversion could run over $108,000 today.

![message-editor%2F1592340613162-1999-cadillac-eldorado-mosler-\_0.jpg](<https://www.thedrive.com/wp-content/uploads/content-b/message-editor/1592340613162-1999-cadillac-eldorado-mosler-_0.jpg>)
*Mosler Twinstar, *RM Sotheby's**

Such price tag, in conjunction with the Twinstar's strange styling and a doubled risk of [popping a head gasket](<https://www.thedrive.com/accelerator/21588/a-rookie-at-24-hours-of-lemons-finding-fulfillment-community-and-satan-in-my-first-endurance-race>), is likely what resulted in its atrocious sales. Only five were ever sold, three reportedly to a single ultra-wealthy kook who wanted to keep driving with a radiator shot out, and one to Jay Leno according to [RM Sotheby's](<https://rmsothebys.com/en/auctions/fl15/fort-lauderdale/lots/r0142-1999-cadillac-eldorado-mosler/562509>). Such rarity makes their value today hard to gauge, though [sales in the mid-late Twenteens](<https://bringatrailer.com/2015/12/28/sixteen-cylinders-awd-1999-cadillac-eldorado-twinstar-by-mosler/>) suggest sale prices in the mid-to-upper five figures are typical. For what's probably the last 16-cylinder Cadillac, maybe those prices aren't too batty.

![message-editor%2F1592341341469-1947980\_369216233220092\_1267345984\_n.jpg](<https://www.thedrive.com/wp-content/uploads/content-b/message-editor/1592341341469-1947980_369216233220092_1267345984_n.jpg>)
**"King Daddy Caddy - Cadillac of the day." on Facebook**

*Got a tip? Or a friend who would let us drive a Mosler Twinstar? Send us a note: tips@thedrive.com*

## Author
James is a former staff writer for The Drive. He has changed the conversation around electrification, debunked misinformation online, and become a prominent hunter of what he calls "automotive cryptids."

### Author social links  
[Instagram](<https://instagram.com/jamesgilboy>)