When it was first launched, the Chevrolet Beretta was a sharp-looking coupe. Its powertrain line-up, however, was nothing exceptional. It used the same four-cylinder and V6 engines that powered tens of thousands of Cavaliers, Celebrities and Corsicas. Even the racy-looking GTU, despite its firmer suspension, used the same corporate 2.8 V6 as countless GM products. What the Beretta needed was a performance engine, and that’s just what Chevrolet gave it for 1990.
Enter the GTZ. Available only with a five-speed manual transmission, the GTZ used the high-output LG0 version of the Oldsmobile-developed, double overhead cam, 16-valve Quad 4. Displacing 2.3 liters, the LG0 produced 180 hp at 6200 rpm and 160 ft-lbs at 5200 rpm. Though it was down 20 ft-lbs on the ’90 Beretta’s flagship 3.1 V6, it produced 45 more horsepower and had a better 0-60 time – Motor Trend was able to hit 60mph in 7.6 seconds, compared to 9.3 seconds in a V6 Beretta. Say what you will about the Quad 4 – it had reliability issues, it was unrefined – but it gave the Beretta a kick in the pants.
As Oldsmobile had developed it, the Quad 4 first appeared in the Cutlass Calais. It soon proliferated throughout the Buick, Chevrolet and Pontiac line-ups in regular LD2 and high-output LG0 variants. Buick only got the less-powerful LD2 (and only in the Skylark), while Chevrolet only got the high-output LG0 and only in the Beretta.
Costing $1250 more than a Beretta GT 3.1, the GTZ added a firmer FE7 suspension tune and a fresh look of its own. The grille was blocked off and there was a unique front air dam and rear spoiler, body-colored 16-inch wheels, and a complete absence of brightwork. The GTZ also added standard air-conditioning, fog lights and a leather-wrapped steering wheel. Alas, the interior was almost identical to regular Berettas with its drab plastics and slabby, shelf-like dashboard. Fortunately, all Berettas received a redesigned and more attractive dashboard and driver’s airbag for 1991.
Critics found the L-Body Beretta GTZ to be a more cohesive package than the related N-Body cars. The Quad 4 was said to be less prone to noise and vibration, while the Beretta had superior roll stiffness to sporty Calais and Grand Am variants. There were still complaints about the GTZ’s peaky and noisy nature, however, and Consumer Guide also dinged the Beretta for its “uncoordinated suspension” even though they found it overall to be fun to drive.
In their 1990 Bang For Your Buck special, Motor Trend found the Beretta GTZ to be “more neutral, and thus, more fun to drive than the Calais and Grand Am”. Motor Trend did, however, criticize the Beretta’s “mushy brake feel” and “notchy shift action”. Despite a slalom time slower only than the Nissan 300ZX Turbo – not bad for a fleet of 20 test cars – the Beretta GTZ scored only 15th in fun factor. Still, its 0-60 time was just 0.3 seconds off a more expensive Ford Thunderbird Super Coupe and its list price of $13,750 was around a grand below rivals like the Eagle Talon TSi and Ford Probe GT.
Given Chevrolet’s higher sales volumes and the fresher look of the Beretta vis-à-vis the N-Body cars, it wasn’t surprising to see the Beretta GTZ to storm past its cousins in sales. Oldsmobile shifted just 818 Cutlass Calais Internationals with the LG0 in 1990 while Pontiac managed a more impressive 4921 LG0-equipped Grand Ams. As for Chevy, they shifted 13,239 Beretta GTZs, accounting for around 7.5% of all Beretta sales.
The four-banger GTZ’s glory was short-lived. The regular Beretta’s 3.1 V6 became a $119 credit option for 1991 and, despite only being available with a three-speed automatic, it appears to have been more popular than the mandatory-manual Quad 4. Just 3010 GTZs were produced for 1991 with the Quad 4 and this number continued to shrink during the GTZ’s run. In 1993, just 1.5% of Berettas used the engine.
For 1994, the GT and GTZ were replaced with the new Z26. Much as the Cavalier Z24 had used a V6, the Beretta Z26 was available with the Quad 4, the last number in the trim name merely indicating the Beretta’s position in Chevrolet’s sporty car line-up. The Quad 4 lost 10 horses for its final year but increased its sales slightly, 896 Z26s rolling off the factory line with the Quad 4. Pontiac, conversely, shifted three times as many LG0-equipped Grand Ams.
By this point, Beretta sales were in terminal decline. The Quad 4 Beretta was gone after ’94 and the entire line discontinued in 1996, the same year a new LD9 variant of the Quad 4 arrived, finally featuring balance shafts but down 20 horses from the last of the LG0s. Crucially, the addition of balance shafts improved refinement considerably and the LD9 engine lasted into the 21st century.
It’s likely the Beretta GTZ’s lack of an automatic transmission did it in more so than its rev-hungry four. The Beretta’s ageing body probably didn’t help, either, especially in such a fashion-conscious segment. Then there were the cheaper Cavalier Z24 and Beretta GT models, available with automatic transmissions and featuring V6 engines, relatively rare for the segment.
That was a multitude of factors to contend with before you even got to the engine, which was known to suffer from cracked heads and blown head gaskets. Nevertheless, the Quad 4 had outputs that were very impressive for a naturally-aspirated four in the early 1990s and remain impressive today. The Beretta GTZ was also an attractive coupe with a very different vibe from a cheaper V6-powered Cavalier Z24 or a similarly-priced, V8-powered Camaro RS, plus some meaningful suspension improvements over lesser Berettas. Alas, both because of and in spite of its engine, it probably wasn’t the best buy in the sport coupe segment or even within the Beretta line-up.
1990 GTZ photographed in Crescent City, CA in June 2019.