Some of the many inquiries I receive from Old Cars Weekly readers request production numbers and numbers of surviving cars. I can usually help with production numbers, but when it comes to the total number of cars from a specific manufacturer that survive, it's impossible to determine except in two cases: Tuckers and Duesenbergs. These two makes of cars are so low-production and have such a following, many people track each cars' history and whereabouts, and have been doing so for so long, it would be truly amazing if a completely unknown car emerged from a barn or an estate in South America.

The most recent production question came from reader Joe Boccio, who owns two 1968 Pontiac Grand Prix models, one of which is euqipped with a 375-hp 428-cid witha  four-speed. He says, "I do know it is one of 655 produced this way out of 31,711, but I would like to know how many are left on the road. Do you know of a way to obtain a current vehicle registration count (by state or the whole country) of a specific year, make and model?"

Determining exactly how many of nearly any car is almost impossible. A good example of the bad types of estimating is in a recent Sound Your Horn, in which a reader wrote in to say he had a Stutz of the same year/make/model featured in OCW. (In the story, we stated the Stutz was believed to be the last of that kind left. Turns out, that’s not the case. Because of such instances, we’re always careful how we word estimates of remaining cars.)

The only good estimates of remaining cars come from clubs that have registries for specific cars that were low production, and they are never 100 percent, because not everyone is a member, or has heard of the registry. Also, some people simply do not want to give out their information to such registries.

The best estimate people use for determining a survival rate is 10 percent. Given the effects of rust and accident damage, the frequency of salvaging high-mileage cars, etc., this is probably the closest we’ll ever be able to get. So, in this case, there are probably around 65 1968 Pontiac Grand Prix models with the 428-cid/375-hp/4-speed combination left.

However, Pontiac owners should be happy to know that few people can find such specific production numbers as Boccio and other Pontiac owners can for their cars, and that you have access to Pontiac Historical Services for documenting your car — it’s a luxury few owners have for documenting their cars.

I've never been impressed with the Toyota Prius' fuel mileage knowing that, 20 years ago, Geo Metros were getting more than 50 mpg without all of the batteries and maggot-shaped styling features of the Prius. (I've also never been so underwhelmed by the look and feel of a car's interior as I was with the Prius.) So any way to give alternatives to one of these cars is always a plus for me, especially when it comes from the Ford family. Here's the latest news I have received over the wire showing the results of Ford's green efforts, led by William Clay "Bill" Ford Jr. (For the record, Bill Ford has been environmentally conscious well before Toyota has been loading its lots with gas-sucking TUNDRA's, SEQUOIA's and the like.)

Fusion Hybrid Averages 81.5 MPG, Sets World Record with 1,445 Miles on Single Tank of Gas

- Drivers trained in mileage-maximizing techniques achieve 1,445 miles on a single tank of gas in a 2010 Ford Fusion Hybrid - averaging 81.5 mpg in Washington, D.C. - and set world record for gasoline-powered, midsize sedan

- The Fusion Hybrid 1,000-Mile Challenge proves that fuel-efficient driving techniques can nearly double a vehicle's EPA-rated fuel economy

- The demonstration of the Fusion Hybrid's ultra high-mileage potential also raised more than $8,000 for the Juvenile Diabetes Research Foundation

WASHINGTON, April 28 /PRNewswire-FirstCall/ -- Drivers trained in mileage-maximizing techniques such as smooth acceleration and coasting to red lights were able to get an extraordinary 1,445.7 miles out of a single tank of gas during a fund-raising effort in Washington, D.C. that concluded today. They did it by averaging 81.5 miles per gallon in an off-the-showroom floor, non-modified 2010 Ford Fusion Hybrid, the most fuel-efficient midsize car in North America - nearly doubling its U.S. certified mileage.

The Fusion Hybrid 1,000-Mile Challenge started at 8:15 a.m. EDT on Saturday, April 25, from Mount Vernon, Va., and ended this morning at 5:37 a.m. on George Washington Parkway in Washington, D.C. After more than 69 continuous hours of driving, the Fusion Hybrid finally depleted its tank and came to a stop with an odometer reading of 1,445.7 miles - setting a world record for gasoline-powered, midsize sedan.

The challenge team, which included NASCAR star Carl Edwards, high mileage trailblazer Wayne Gerdes and several Ford Motor Company (NYSE:F) engineers, raised more than $8,000 for the Juvenile Diabetes Research Foundation (JDRF) by exceeding the goal of 1,000 miles on a single tank of gas. The Fusion Hybrid's official estimated range is approximately 700 miles per tank.

"Not only does this demonstrate the Fusion Hybrid's fuel efficiency, it also shows that driving technique is one of the keys to maximizing its potential," said Nancy Gioia, director, Ford Sustainable Mobility Technologies and Hybrid Vehicle Programs. "The fact that we were able raise much needed funds for JDRF while raising the bar on fuel efficient driving performance made the effort doubly worthwhile."

Maximizing mileage

A team of seven drivers prepared for the challenge by learning a few mileage-maximizing techniques, most of which can be used in any vehicle to improve fuel economy, but are especially useful in the Fusion Hybrid where the driver can take advantage of pure electric energy at speeds below 47 mph.

CleanMPG.com founder Wayne Gerdes, an engineer from Illinois who coined the term "hypermiling" to describe the mileage-maximizing techniques, provided the pointers. They include:

  --  Slowing down and maintaining even throttle pressure;
  --  Gradually accelerating and smoothly braking;
  --  Maintaining a safe distance between vehicles and anticipating traffic
      conditions;
  --  Coasting up to red lights and stop signs to avoid fuel waste and brake
      wear;
  --  Minimize use of heater and air conditioning to reduce the load on the
      engine;
  --  Close windows at high speeds to reduce aerodynamic drag;
  --  Applying the "Pulse and Glide" technique while maintaining the flow of
      traffic;
  --  Minimize excessive engine workload by using the vehicle's kinetic
      forward motion to climb hills, and use downhill momentum to build
      speed; and
  --  Avoiding bumps and potholes that can reduce momentum

"You become very aware of your driving because you're constantly looking for opportunities to maximize mileage, and a more aware driver is a safer driver, too," said Gil Portalatin, Ford hybrid applications manager.

In addition, it is important for Fusion Hybrid drivers to manage the battery system's state of charge through the use of regenerative braking and coasting, and balancing the use of the electric motor and gas engine in city driving to avoid wasting fuel.

Fusion Hybrid drivers also can stay more connected to the hybrid driving experience with Ford's SmartGauge(TM) with EcoGuide, a unique instrument cluster that helps coach drivers on how to optimize performance of their hybrid.

The Challenge

The Fusion Hybrid 1,000-Mile Challenge team took turns driving several routes in and around the national capital over the course of approximately three days and nights. The route involved elevation changes, and ranged from the relatively open George Washington Parkway to a 3-mile stretch in the heart of the city that is clogged with roughly 30 traffic signals.

"The Fusion Hybrid works brilliantly," Gerdes said. "When you don't need acceleration power while driving around town, the gas engine shuts down seamlessly. There's not another hybrid drivetrain in the world that does that as effectively. The Fusion engineering team really knocked it out of the park."

Ford NASCAR star Carl Edwards took time away from the high speed world of professional car racing to contribute to the Fusion Hybrid team's success in D.C.

"It was exciting to be an active part in this challenge. The fact that it will help spread the word about the Fusion Hybrid's great mileage, and help out a great charity, makes it even more special," said Edwards, whose '99' team has used fuel-saving techniques to win races. "There's no question that the Fusion Hybrid will help consumers save fuel when they drive it. Having driven the car, I feel strongly about how great it is - so strong that I've purchased one myself."