31 October 2016

Why isn’t the Chevy Corvette ZR-1 worth more?

There’s good news and bad news for anybody who bought a 1990-95 Chevrolet Corvette ZR-1 brand new and still owns it.

The good news is you’re driving one of the best cars General Motors ever built, a corporate Ferrari-beater that would have cost double built by a boutique manufacturer.

The bad news is you still haven’t recovered your original investment of at least $58,995 (over $107,700 in today’s dollars) – and the highest price at auction at this time remains $48,600, achieved by Mecum for a 1995 ZR-1 on January 24, 2015 at Kissimmee.

But cheer up because ZR-1s seem to have bottomed. Most seem to sell between $20,000 and $35,000, but the newest is 20 years old, and prices are on the way up. And well they should be; the 6,939 ZR-1s are the least-appreciated Corvette and the best value in the entire lineup.

 The Corvette reached its nadir in 1975, when emissions strangled the 350-cid V-8 in the C3 to a mere 165 bhp, from nearly double that, just six years earlier. With the fourth generation debuting in 1984 and the development of cross-fire fuel injection, the motor recovered, but still produced only 240 bhp in 1989.

GM decided more power was vital to save the brand, and initially planned to turbocharge the existing OHV V-8. But that wouldn’t yield enough horsepower, so the decision was made to develop a double overhead cam (DOHC), four-valve engine at GM’s Lotus plant at Hethel in England.

However that motor was too wide to be installed from beneath the chassis, like previous Corvette units. So a new engine was developed with an aluminum block, and production handed to Mercury Marine at Stillwater, Okla. The company had excellent quality control and would build 18 engines a day, shipping them to Bowling Green, Ky., for installation.

The new motor was designated the LT5 and developed an astonishing 375 bhp thanks to four overhead camshafts, an 11-to-1 compression ratio and four valves per cylinder. The ZR-1 was capable of 0-60 mph in 4.3 seconds, a 13-second quarter-mile at about 110 mph and 180 mph top speed. Most significantly, the fuel injection system shut down eight of the 16 intake runners until half throttle, so the engine was powerful and flexible, with a 7,200 rpm redline.

Launched at the 1989 Geneva Salon in May, the ZR-1 was built as a coupe, with an optional targa top, and equipped only with a six-speed manual gearbox. The new King of the Hill, as it was initially known, looked like the existing C4, but differed significantly in mechanical details.

The ZR-1 tail was convex, as opposed to the regular Corvette’s concave rear, and the taillights were squared instead of circular. A small ZR-1 badge was affixed below the right rear light. But the wheels were 11-inches wide with 193 mph Z-rated 17-inch tires. To fit those tires, the rear of the car was widened three inches, which necessitated a different rear clip, doors and rocker panels.

The ZR-1 also featured perhaps the first “valet key,” with two settings. In “normal” mode the secondary intake ports were disabled, limiting the engine to about 200 bhp. In “power” mode the output rose to 375-380 bhp.

The base price of a 1990 Corvette was $31,979 and the ZR-1 package added $27,016. That package included power leather seats, 14-setting selective ride and handling, Bose stereo and low tire pressure monitor, but that only added $4,829 to a base car, which means the ZR-1 package cost $22,187. Even though it was easy to top $60,000 with a few other extras, “dealer premiums” (code for price gouging) were common, and some cars sold for $100,000.

Somehow the seed was not sown. GM built 3,049 ZR-1s in 1990, 2,044 in 1991, 502 in 1992 and 448 each of the next three years. The high price of the package was a significant factor, but GM devalued the model with several bonehead moves. While one cannot blame the corporation for raising the base LT-1 engine to 300 bhp in 1992 as rivals’ horsepower also increased, there was no excuse for fitting the ZR-1’s convex tail and square taillights to the base model.

The net effect was to devalue the investment, and several thousand ZR-1 owners suffered the same resale curve as the 1976 Cadillac Eldorado “last ever” convertibles. Accounting for inflation, those original Cadillac owners are STILL underwater.

So should you buy a ZR-1? It depends if you will drive it. The 1993-95 cars were boosted to 405 bhp, and that’s an impressive figure today. The flexible engines are a blast to drive, with maximum power delivered at 5,800 rpm. The ZR-1 is competitive with European supercars of the time and the maintenance is a bargain by comparison.

There are a number of ZR-1s on the market at any given time, and while low mileage trailer queens may have seal issues, regularly exercised cars should be fine. Some unique spares could be problematic, as production was limited (windshields are different, for example). But if you’re planning long-term ownership, hoard what you may need. As far as the Mercury Marine engines are concerned, you’ll need a good mechanic, but they turned out to be spectacularly reliable – I know of one that amassed 250,000 miles without a teardown.

Most ZR-1s have been well cared for but if you’re shopping, check for accident damage. Also, be careful that what you’re buying is a real ZR-1, not just an engine transplant from a crashed car. Real ZR-1s have “Z” as the fifth digit in the VIN, base cars have “Y.”

Except for the tiny lettering on the tail, and a different center brake light, a ZR-1 is a stealth supercar. You may feel like Rodney Dangerfield, but they’ll have to catch you to point that out.

14 Reader Comments

  • 1
    Michbc3 Port St. Lucie, FL November 2, 2016 at 19:30
    I used to love seeing ZR-1s show up at the dragstrip. My 1979 Corvette with an inexpensive, easy to build 383 stroker small block and Doug Nash 5 speed easily sent the wine and cheese guys packing.
  • 2
    Dean Red Deer, Alberta November 2, 2016 at 22:15
    I have 2 x 1990 ZR-1's, and one of them has a dark colored engine. I have been told there was a "Black Widow " version, anybody know how to tell ? It seems a lot faster than the other car. Also, the 1990 ZR-1 set a world record for 24 hr endurance race, averaging about 175 mph, anyone know when that record was beaten and what car ? Unfortunately I was in serious accident and can't easily drive the 6 speed now, so I posted them for sale on Kijiji.
  • 3
    Kevin K Northwood Oh November 3, 2016 at 18:31
    Sorry, but last time I checked there were no fixed roof ZR1s, all were targa tops!
  • 4
    Sal Esposito New Jersey November 3, 2016 at 08:36
    Shhhhhhhh.....This might be my next car if they stay cheap.
  • 5
    Matt Kempton Pennsylvania November 3, 2016 at 12:01
    I still prefer the C-4 Over the all the other iterations since. It's proportions are so right. I'm glad there are so many, I'll be able to afford a nice one again someday. Your spot on about the convex tail lights, GM should have left them unique to the ZR-1.
  • 6
    Ron Orr Richmond, Texas November 5, 2016 at 16:52
    I am the second owner of an all original 1990 ZR1. It currantly has about 60.500 actual miles. I am 72 years old and drive the car around 2000 miles a year. The car has been on the tract at 165 mph. Only problem is air conditioning issues.
  • 7
    Tony Ciminera New Jersey November 6, 2016 at 15:31
    Why did Chevy develop a different windshield? What made it different from the base car?
  • 8
    Rex O'Steen South Carolina November 7, 2016 at 08:47
    I thought Paul's article was very well-written. He painted a fair picture of both the car, the motivations behind its output, and the environmental conditions of the era.
  • 9
    GEORGE Lynn Oregon November 22, 2016 at 15:16
    I see a lot of vette owners bashing the ZR1s and claiming theirs will blow their doors off. I am new to the ownership of a nice 91, red on black with 12k on the clock. And just dropped a dime on a 90 ZR1. It seems to me that these things take very well to great gains in horse power with easily done upgrades. But all that aside,they still remain fully capable of 150mph plus, right out of the box. The engine is a marvel to behold and far ahead of its time. It was that alone that got me to take the plunge. Lift the hood on any c4/c5 and they look the same no matter what you do to them. Lift the hood on the LT5 and you feel your heart pick up a beat or two. You own a rare piece of GM history. Doesn't get any better than that.
  • 10
    Goldcylon Peoria November 22, 2016 at 22:28
    Yes Tony GM did change the windshield for the ZR-1 only. It's a solar windshield because the engine was so large that only an undersized AC compressor would fit so to offset that problem GM engineers solar laminated the windshield to reduce the interior heat load.
  • 11
    ed ramos Florida (FL) November 23, 2016 at 11:10
    nothing pulls like a lt5 at 7k rpm. while all other engines wind down, the lt5 is just getting its breath... dohc... double the valves, double the air,, double the fun. these are not quarter mile cars. these are grand touring top speed cars. if you see one..watch your step.
  • 12
    Graybeard ZR-1 Jupiter Fl. November 28, 2016 at 17:27
    Paul Duchene has written probably the best, most concise, article on the C4 ZR-1 that I've ever read, and I've read them all, being an owner of a 91' ZR-1 since almost new in 94'. A lot of owners always sing the blues about the fact that they should be worth more. I say, so what, I'm keeping mine forever. If those weenies who need an instantly recognizable showpiece to polish, let them pass on the ZR-1, keep the prices low. But if you're a driver and want the fastest factory production Chevrolet of the Twentieth Century, perhaps you should own one. As to the guy with the 383/ 69' from Port St. Lucie, (up the road from me), I would love to show you the a$$ end of mine. Bone stock C4 ZR-1's run about 13.00 flat, and with sticky tires and ones with bolt-ons run in the elevens, or very low twelves (that's a stock block 350, strokers are in the tens). If your old shark is quicker than that, thumbs up. But as to top end, or on a roll, you have.......no chance.
  • 13
    JZ Alabama December 19, 2016 at 22:05
    Unreal that these cars are at the price they are. They were way ahead of their time and still quite possibly the best sounding GM V8 ever produced.
  • 14
    Johnnyesquire Scottsdale January 1, 2017 at 14:26
    Touche' graybeard!!

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