Simanaitis Says

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A 91.2-MPG DATE WITH VERA

FORTY MPG on the highway seems to be the value that everybody lies about these days. Hence, it is with more than just modest satisfaction that I recall my adventure with Peugeot’s VERA, its Vehicule Econome de Recherche Appliquee. I got an official 91.2 mpg in driving VERA from Detroit to Knoxville, Tennessee—way back in 1982.

Super-efficient though VERA was, she wasn’t all that exotic. Instead, she was a wonderful example of incremental engineering, her wealth of aerodynamic refinements bringing a stock Peugeot 305’s 0.44 CD down to 0.32. This first value was typical for a small sedan in 1982; the second, likely average for today’s cars.

VERA

VERA wasn’t some fancy-schmancy concept car; rather, she was an only somewhat modified Peugeot 305 turbodiesel.

VERA’s most noticeable aerodynamic features were her full disc wheel covers, the front fenderwell treatment optimizing flow in this turbulent region and the wing on the rear deck to help control the car’s wake. Less noticeable but important was a subtle recontouring of the car’s front edges. Also, the front side windows had deflectors reducing turbulence at the A-pillars—and also allowing the windows to be open a tad without disrupting the flow. VERA had a full 305 interior, though she was not fitted with a/c. Dieting here and there brought her weight down 400 lb. to a curb weight of around 1730 lb.

VERA’s powertrain was a 1306-cc 62-hp inline-4 turbodiesel mated to a 5-speed manual gearbox and driving her front wheels. I recall gearing wasn’t all that tall.

My adventure from “Motown” to Knoxville was in May 1982, coinciding with the latter city’s International Energy Exposition. According to Google Maps, Detroit to Knoxville is a straight shot south on Interstate 75, a distance of 513 miles with a Google driving time of 7 hours 36 minutes, figured at an average speed of 67.5 mph.

Goo

Nothing fancy in VERA’s route from Detroit to Knoxville: Get on I75 South, steer more or less straight and get off at the World’s Fair exit. Our speed, though, was atypical.

Based on previous calibration drives, we knew that VERA’s best economy occurred around 30-35 mph—and that was our target speed. Our convoy of pace cars, at a distance front and back, with VERA and an official-certification car in the middle, made this feasible to various highway authorities.

The speed also lengthened my driving time to 15 1/2 hours, non-stop but for a single 30-minute break in the middle of the night. I got to practice mon français along the route, what with a Peugeot engineer in the passenger seat. His job was to monitor fuel-flow instrumentation, figure real-time consumption and help develop our optimal driving style.

The basic strategy was simple: Balance the highest gear and lightest accelerator pedal to maintain the desired speed. This was easy-peasy through billiard-table-smooth Michigan and Ohio, 5th gear and VERA’s turbodiesel running as lean an air-fuel ratio as my right foot could arrange.

Our convoy had radio contact, and this proved crucial once we encountered the rolling hills of Kentucky and Tennessee. Any of these gentle grades could be taken in 4th or 3rd with the same light foot, but the trick was to decide just when to downshift. Correlating downshift strategy with fuel flow, we developed an added visual clue: Downshift precisely when our chase car saw VERA emit the tiniest trace of diesel smokiness.

This strategy—and the steadiest right foot for hour after hour—gave VERA her impressive 91.2 mpg at an average speed of 33.1 mph.

I recall we arrived at the World’s Fair in mid-afternoon, celebrated at the French Pavillion, then hit the hay. Tight schedules had us leaving the next morning for Detroit, so I never did see much of the place.

On the way north, we celebrated our Double Nickel national speed limit by averaging 54.9 mph. VERA—and I—did this at an impressive 73.7 mpg. Formidable! ds

© Dennis Simanaitis, SimanaitisSays.com, 2012

One comment on “A 91.2-MPG DATE WITH VERA

  1. Bill Urban
    December 21, 2012

    And obviously accomplished without one of those secret carburetors. Todays’ interesting Peugeot – a model 3008 diesel hybrid, in the 70s’ per imperial gallon, and the motors driving the rear wheels not only provide all wheel drive when needed, but even provide some mitigating thrust when the automated manual changes gears. One would hope too that any turbo lag might be mitigated. Quite impressive but unfortunately Peugeot (7% owned by GM) continues to suffer in the contracting European market.

    On aerodynamics, some scale – a typical older generation “big rig” with no aero design benefit and a 13′ tall trailer needs about 100HP just to overcome aero drag at highway speeds. And todays’ best aerodynamic designs cut that by ~50%.

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This entry was posted on December 21, 2012 by in Classic Bits and tagged , , .
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