Petrol Opel had introduced a new generation of petrol engines in 1966 with the
Rekord B and these were the engines that reappeared in the Rekord D. As before, the stroke length was fixed at 69.8 mm: differences in engine size were achieved by varying the cylinder bore. The engine featured an unusual
Camshaft in Head (CIH) configuration. The chain-driven camshaft was positioned directly above the cylinders but this was not a conventional
ohc design. The camshaft operated the valves using rocker arms because the camshaft itself was positioned too low above the cylinders to permit direct action from the camshaft on the valves ends. One reason for this may have been cosmetic. Opel's so-called "CIH" engine configuration allowed the Rekord to incorporate the low bonnet lines that style-conscious product development departments called for. Although the Rekord D shared its wheelbase with its predecessor, in other respects it respected the tendency of Opel Rekords to move slightly upmarket with each new model. The Rekord D was heavier than the Rekord C and the previous model's 1492 cc engine was no longer offered. The smallest power unit at launch, and the one that would be the top seller with this model, was a 1698 cc engine with the low 8.2:1 compression ratio and as on the predecessor. The 1698 cc unit was also offered with a twin barrel carburetter and a compression ratio of 9.8:1, offering a maximum power output of and much improved torque. Drivers of this "1700 S" engined Rekord had to pay for higher octane fuel, however, and there was also a price to be paid in terms of reduced fuel economy. Customers wanting more performance from their Rekord could specify the "1900 S" engine of 1897 cc, providing a maximum power output of supported by a 9.8:1 compression ratio and a twin chamber carburetter. Like the high compression "1700 S" unit, the "1900 S" needed high octane fuel, but it did provide a top speed of 165 km/h, making it good for more than 100 mph in non-metric export markets. This was the fastest Opel Rekord D on launch, there being no longer any six-cylinder engined Rekords. Anyone wishing to buy a Rekord bodied car with a six-cylinder engine would need to pay also for the enhanced specification of the six-cylinder
Opel Commodore with which the Rekord again shared its body. Early on in the Rekord D's production, Opel also released
SAE power figures alongside the
DIN norm, with the 1900 S engine producing a claimed at 5200 rpm and at 3800 rpm under SAE standards. This was the only engine offered by Opel's Japanese importer. In 1975, the
Petrol lead law came into force, more than halving the amount of
lead that could be added to petrol in
West Germany. Similar legislation came into effect in key export markets across western Europe. For the oil companies the addition of lead to fuel provided a simple and inexpensive way to vary octane levels. Having lobbied vigorously against the legislative restrictions, they now responded by reducing fuel octane ratings on the forecourts. The 98 octane fuel on which the Rekord's high compression engines depended was reduced in the super grade fuel normally available, while low lead 98 octane fuel became hard to find and very expensive. For the entry level Opel Rekord "1700 N" claimed maximum power was reduced, in 1975, by 6 PS to . The high compression "1700 S" version was withdrawn, and the range was extended by a low compression version of the 1897 cc unit, sometimes known as the "1900 N" and providing a maximum power of and a compression ratio of just 7.6:1. The "1900 S" high compression ratio version of this engine had its maximum power reduced from reflecting a compression ratio reduced from 9.8:1 to 8.8:1, which enabled it to use the new reduced octane "super" grade fuels without
knocking. In some markets, such as Sweden and Switzerland, emissions controls were even stricter and the new engine produced only , while the 1700 engine was discontinued there. To compensate for the loss of performance on the "1900 S" Opel now increased the cylinder bores further and introduced, in September 1975, a 1979 cc version of the engine for their Rekord "2000 S". of maximum power was claimed for what was the fastest Rekord from this generation. Neither its power nor its performance matched the "1900 H" version of the old 106 hp
Opel Rekord C however, which presumably reflected changed priorities in the market place following the fuel shortages and price shocks of the mid 1970s.
Diesel September 1972 saw the introduction of the first diesel powered Opel Rekord, with which the manufacturer launched a determined assault on the lucrative stranglehold that Mercedes-Benz enjoyed over the taxi market in West Germany and, to varying extents, in many of the export markets where the firms competed. The four cylinder 2068 cc diesel unit was not based on the Rekord's "CIH" petrol engines, but was a newer design. The "Caravan" estate was originally not available with the diesel engine, but a five-door diesel estate was added to the lineup at the 1973
Frankfurt Motor Show (September). The fuel feed system employed a
Bosch diesel injection pump. The unit's basic architecture applied a conventional
ohc configuration which made it a little taller than the Rekord's petrol engines, and diesel powered Rekord Ds are therefore easily distinguishable by the hump shaped ridge along the centre of the bonnet. For certain export market, notably Italy, where the 2-litre engine size was a critical threshold in terms of car tax rates, a smaller diesel unit became available from December 1974. The smaller unit shared the 85 mm stroke of the 2068 cc unit, but the bore was reduced from 88 mm to 86.5 mm, giving rise to a 1998 cc overall displacement. Maximum power in the smaller diesel came down from the 2068 cc car's to . This was a first outing for the 2-litre diesel engine which from 1978 was offered in a diesel powered version of the
Opel Ascona. ==Transmission==