THE TROUBLE BEGINS
The NSU Ro80 was an entirely new product from a company that hadn’t sold an executive car in conscious memory, powered by a bleeding-edge engine and rushed into production. What could possibly go wrong? In all fairness, if we discount the engine, the answer is “Surprisingly little”; even the curious Saxomat transmission was generally reliable. Der Wankelmotor, however, quickly established itself as a problem child, threatening to overshadow the Ro80’s other virtues.
Despite the rotary’s apparent simplicity, long-term testers soon complained that the KKM 612 could be frustratingly difficult to keep in proper tune. If the twin Solex carburetors were even slightly out of adjustment, the result would be hesitation and flat spots, which took a fine touch to correct. The spark plugs were another headache; the rotary had a unique flair for fouling its plugs in slow driving. The plugs’ position in the combustion chamber made it impossible to clear them with a burst of speed as one could with a piston engine, so the only recourse was to remove the plugs and clean or replace them. If most of your driving was on open roads, that was not a major concern, but regular urban commuting limited plug life to 5,000 miles (8,000 km) or less and the specified plugs were very expensive, 10 to 12 times the cost of a standard plug.
Those shortcomings were tolerable, if annoying, but they were followed by a rash of more serious engine problems, including failure of the apex seals and/or eccentric shaft bearings, often at less than 25,000 miles (40,000 km). Rather than attempting to repair or rebuild those engines, NSU generally opted to replace them (sometimes more than once) under and sometimes beyond the 20,000-mile (32,000-km) factory warranty. That was inevitably very expensive, and while NSU’s rather generous engine replacement policy was intended to appease nervous or angry customers, it actually served to drag down the car’s reputation.
The root of the problem (aside from the Ro80’s overly hasty development) was that NSU had misjudged its customers’ real-world driving habits. The company apparently assumed that because the Ro80 was a large and thirsty car, most owners would use it in a relatively sedate fashion, mainly for long trips. In practice, the Wankel’s eagerness to rev encouraged owners to drive far more aggressively, with frequent excursions to or beyond the 6,500 rpm limit. While the engine was so smooth that it would exceed its redline without apparent complaint, such treatment exposed the limitations of the oil system, eventually leading to bearing damage. Stop-and-go driving, meanwhile, not only fouled the plugs, but also played hob with the engine’s clever three-piece, self-adjusting apex seals, particularly with liberal use of the manual choke.
While NSU subsequently made changes that at least mitigated the Ro80’s major weaknesses, the damage to the car’s image and the company’s bank account was considerable. NSU was already overextended and the Ro80’s massive warranty costs only made a bad situation worse. The ultimate price would be the company’s fiercely guarded independence.
One of NSU’s ongoing challenges was that while Wankel licensing was a crucial source of revenue, the company was not unlike a minnow trying to do business with whales. The rotary engine had obvious value, but it undoubtedly occurred to some of NSU’s larger prospective licensees that it might be simpler to absorb the whole company and its patents rather than pay royalties. Von Heydekampf, however, had always refused to be intimidated, adopting a take-it-or-leave-it attitude toward negotiations. The NSU board strenuously resisted any attempts at outside takeovers, although Citroën did acquire about 10% of NSU through the two companies’ Comobil and Comotor joint ventures (a share acquired in 1968 by Fiat).
By early 1969, however, NSU’s position was becoming untenable, so von Heydekampf reluctantly entered discussions with Kurt Lotz, the new managing director of Volkswagen. Lotz, who had succeeded VW’s conservative Heinz Nordhoff in the spring of 1968, was still looking for Volkswagen’s post-Beetle direction and was very interested in expanding Volkswagen’s product range and production capacity. NSU needed capital very badly, but the Neckarsulm firm was still very reluctant to sacrifice any of its independence.
The compromise Lotz eventually struck with NSU was a merger with Auto Union (Audi), the Ingolstadt automaker in which VW had acquired a controlling interest back in 1964. The deal promised greater autonomy for NSU and did not require the approval of Volkswagen’s supervisory board, with which Lotz seldom saw eye to eye for various political reasons.
The merger, announced in March 1969, created a new company, Audi-NSU-Auto Union, chaired by von Heydekampf and initially holding just under 60% of NSU stock. While a majority of NSU stockholders approved the deal, a small but vocal minority strenuously opposed it, and German law allowed those minority shareholders to demand significant concessions. Among these was an agreement providing genusscheine, profit shares, to NSU’s stockholders, giving them a substantial percentage (initially 40%, subsequently raised to almost 70%) of the company’s revenues from the Wankel engine for the next decade. Another concession was that Volkswagen would not be able to use the rotary engine in its own products without paying license fees to Audi-NSU-Auto Union.
In the short term, Lotz was more interested in NSU’s piston-engined Typ 70, which had been delayed and then briefly canceled around the time of the merger, first for lack of funds and then because the car would have competed directly with Volkswagen products, including the Audi 100. Lotz decided to resurrect the project and transfer it to Volkswagen, albeit with many ‘minor’ revisions that ultimately cost nearly twice as much as NSU had spent developing the car in the first place. It was launched in the fall of 1970 as the Volkswagen K70.
That move added to the displeasure of the minority stockholders, who were already infuriated by many provisions of the merger agreement, most particularly the rather modest option price set for NSU’s remaining stock. Led by the Israeli British Bank, the minority shareholders eventually took the matter to court, an acrimonious case not fully resolved until 1971, around the time Kurt Lotz resigned. NSU may have ended up in the belly of the whale — Audi, and by extension Volkswagen — but it left the whale with a certain amount of indigestion.
Following the merger with Audi, NSU continued developing the Wankel engine and working to resolve the Ro80’s problems. In the fall of 1969, the Ro80 received a new and much cheaper transistorized ignition system with a single coil and one spark plug per chamber along with an improved apex seal design. The latter was only an interim measure, followed in mid-1970 by a thorough update of the initial three-piece design using Ferro-TiC seals that NSU claimed were an order of magnitude more durable than the originals.
At the same time, the oil system was revised to provide better protection for the eccentric shaft bearings at high rpm, supplemented a year later by a dashboard buzzer to warn of over-revving. An automatic choke was added in 1972 and for 1973, the twin carburetors gave way to a single two-throat Solex 32DTI TS; output increased slightly, to 115 hp (86 kW) and 122 lb-ft (165 N-m) of torque. All cars now had emissions controls, including a thermal reactor similar to that used by Mazda, but NSU had never had much of a U.S. presence and we doubt that many Ro80s were formally imported after about 1970. It was almost certainly gone by the 1973 model year, as the Ro80 did not meet the new U.S. 5 mph (8 km/h) bumper standards.
Those changes made the Ro80 much more reliable than it had been (if still not wholly trouble-free), although its appetite for fuel, oil, and spark plugs was not abated. However, it was not easy to overcome the Ro80’s bad reputation, particularly with the alarming reports in the press and editorial cartoons in German magazines showing NSU drivers greeting each other with hand signals to indicate how many engines their car had had (a practice many English-language histories subsequently reported as fact). Sales for 1970 were down nearly 20% from the Ro80’s 1969 peak and 1971 sales fell a further 50%.
Business rallied in 1972 and 1973, but with the Wankel’s considerable thirst, the OPEC embargo in late 1973 and early 1974 was crippling. The Ro80 was already expensive to run and fuel shortages made its sales a very difficult proposition in Europe. Production dropped to fewer than 1,200 units in 1974 and about 1,800 in 1975. Constant price escalation probably didn’t help: the list price in Germany climbed from just under 18,000 DM (about $6,800) in the spring of 1973 to nearly 20,000 DM (about $7,700) by the fall of 1974. By mid-1975, the Ro80 had also disappeared from the U.K. except by special order.
By then, NSU’s piston-engined cars were all dead, replaced on the assembly lines by Audi products. The K70’s days were numbered: its execution had been flawed, its performance was disappointing, and being sold as a Volkswagen meant that NSU’s original plan to offer it with a rotary engine (perhaps as an answer to the BMW 2002) never came to fruition. The K70 finally died in May 1975, having sold around 211,000 units.
The joint ventures between NSU and Citroën also came to nothing. The sole product of the Comobil venture was the Citroën M35 (essentially an Ami 8 with a single-rotor Wankel engine), a road-going research project of which only a few hundred were built. Comotor’s two-rotor KKM 622 engine (derived from the Ro80’s KKM 612) was a costly flop, used only in the ill-fated Birotor version of the Citroën GS, and plans to sell the engine to other automakers never materialized.
Despite all that, the NSU Ro80 was not dead. It received more changes in mid-1975, including new taillights and new bumpers, and in 1977 the Saxomat transmission received new internal gear ratios. The latter modification foreshadowed Audi-NSU’s ambitions for a second-generation Ro80 — something that had been rumored in the press for several years. The new Ro80 was to feature a larger, more powerful engine with a geometric displacement of about 1,500 cc (92 cu. in.), aimed at six-cylinder piston-engined rivals.
NSU’s original plans were for the new Ro80 to use a three-rotor version of the KKM 612 engine, the KKM 619, giving a total displacement of 1,493 cc (91 cu. in.). Further investigation suggested that it would be easier and cheaper to create a new two-rotor engine using a larger rotor diameter to give the same 1,493 cc swept volume. The result was the KKM 871 (known as EA871 in Audi/Volkswagen parlance), which was good for 170 to 180 PS (125 to 132 kW) in preproduction trim. The big engine, prototypes of which were tested in Audi 100 development mules, provided much better performance than the smaller KKM 612 and attracted interest from a number of other automakers. Two EA871A engines, de-rated to 150 PS (110 kW), even found their way into prototypes of the RFP Fanliner, a small acrobatic aircraft.
While the EA871 project enjoyed some support within NSU-Audi — leading to plans to use the new engine in the new C2-platform Audi 100/200 as well as a new Ro80 — technical director Ferdinand Piëch was increasingly skeptical about the Wankel’s viability in the European market. Piëch felt (correctly, as it turned out) that diesel was a better bet than the rotary, which still suffered from relatively poor thermal efficiency and inherently heavy fuel consumption. (Based on the SAE thermal equivalency formula, the EA871 would have been comparable to a 4.5-liter (273 cu. in.) piston engine and probably very thirsty by European standards.) Although Piëch eventually succeeded in ending Wankel development, it was not a universally popular decision. According to writer Martin Buckley, some senior company executives continued to favor cars powered by preproduction EA871 engines well into the 1980s. A few EA871 engines later found their way into private hands.