Michigan test archive · Comparison 2
1983 Chevrolet Impala vs 1983 Chevrolet Impala (Canadian)
The same Impala model with the same 350 four-barrel, in its US-market and Canadian-market versions, run at the same proving ground on the same day. The Canadian car was tested “because they have a different emissions package”.
The short answer
On the 4 measures both cars share, the Canadian Impala was ahead on all 4: 0–60 mph, 0–100 mph, quarter mile and distance to reach 100 mph.
Michigan’s scoring: the US Impala was scored, and its total weighted score, −0.767, was the lowest of the five cars Michigan scored. The Canadian Impala was tested only for acceleration and top speed and was not scored, so Michigan did not rank the two against each other. The bids were unopened when the book went to print, so the book records no award.
The measures are the ones the head-to-head table below compares for both cars (marked ▲, or level); figures the rules box leaves uncompared or compares only with a caution (such as fuel figures from different sources) are not counted, and a figure worked out from another, such as a 60–0 distance from the braking rate, is not counted twice. Neither line says which car was the better police car; that depends on what the car is for.
Meet the two cars
1983 Chevrolet Impala 350
The US-market Impala, sales code 1BL69, with the 350 V8, a four-barrel carburettor and single exhaust, 155 horsepower at 3,600 rpm, and the 700R4 automatic with overdrive and a lock-up converter on a 3.08 axle; test weight 3,993 lb. It was one of the five cars “competing against the Michigan State Police specifications” and ran every test. Its total weighted score, −0.767, was the lowest of the five. The bids were unopened when the book went to print, so there was no award.
1983 Chevrolet Impala 350 (Canadian)
A Canadian-market Impala with the same sales code, 1BL69, and the same 350 V8, four-barrel carburettor and single exhaust, rated at 165 horsepower at 4,000 rpm, with the 350C automatic (lock-up converter, no overdrive) on the same 3.08 axle; test weight 3,839 lb. The preface lists it among “Three Canadian vehicles” that “were also tested for acceleration and top speed”. It was not braked, did not run the road course and was not scored.
Why these two
It is the same model and the same engine size in two market versions, tested on the same day: the book says the Canadian cars were submitted “because they have a different emissions package”. It is one of three US and Canadian pairs in the 1983 book; the Malibu and the Gran Fury with the Canadian Caravelle are the others. The Canadian car was quicker at every 10-mph step from 30 mph on. The book does not say why, and its own data sheets show the two cars differed in more than their emissions equipment.
The rules for this comparison. ✓ compared · ! compared with a caution · ✕ not compared
- Same test. Both are in the 1983 book. Acceleration and top speed were run at the Chrysler Proving Grounds on 18 September 1982: the US Impala at 9:48 a.m. (52 °F, wind 8 mph), the Canadian Impala at 4:30 p.m. (62 °F, wind 8 mph).
- Acceleration. Four-run averages, two runs in each direction “to allow for wind direction”.
- Top speed. Shown but not compared. The Canadian car’s run sheet says: “Vehicle reached a top speed of 107.1 mph. The top speed then steadily decreased due to mechanical difficulties.”
- Laps. Only the US Impala ran the road course.
- Braking. Only the US Impala was braked. The book says the Canadian cars were not braked “as their braking system is identical to their U.S. counterparts and their testing would be redundant”.
- Speed limiters. The 1983 book marks no speed limiters.
- Scored and rated. Only the five cars run against the specification were rated and scored; the Canadian Impala was not.
- Fuel economy. The book prints EPA figures for the US car only; its footnote says data on Canadian vehicles was not available.
Head to head
| Measure | US Impala | Canadian Impala | Difference | Note |
|---|---|---|---|---|
| 0–60 mph (s) | 11.67 | 11.03 ▲ | 0.64 s | |
| 0–100 mph (s) | 42.51 | 36.65 ▲ | 5.86 s | |
| Quarter mile | 18.55 s @ 73.50 mph | 18.30 s @ 76.50 mph ▲ | 0.25 s | |
| Distance to reach 100 mph | 0.84 mile | 0.71 mile ▲ | 0.13 mile | |
| Top speed (mph) | 115.0 | 107.1 | — | not compared: Canadian car’s mechanical difficulties |
| Lap average (12 of 16) | 1:32.21 | not run | — | not compared |
| Braking rate, average (ft/s²) | 23.222 | not braked | — | not compared |
| 60–0 from that rate (ft) | 166.7 | not braked | — | computed; not compared |
| EPA city / highway / combined (mpg) | 15 (14.8) / 25 / 18 | not available | — | not compared |
| Ergonomics (points) | 188.43 | not rated | — | not compared |
| Total weighted score | −0.767 | not scored | — | not compared |
The run to 100 mph
Each point is a four-run average from the book’s Table 3. The US Impala reached 20 mph 0.03 seconds sooner; from 30 mph on the Canadian car was ahead, and by 100 mph it was 5.86 seconds ahead.
Every 10-mph step, in seconds
| 0 to… | US Impala | Canadian Impala | Gap |
|---|---|---|---|
| 20 mph | 2.51 | 2.54 | 0.03 |
| 30 mph | 4.09 | 4.08 | 0.01 |
| 40 mph | 6.09 | 5.91 | 0.18 |
| 50 mph | 8.69 | 8.30 | 0.39 |
| 60 mph | 11.67 | 11.03 | 0.64 |
| 70 mph | 16.08 | 14.75 | 1.33 |
| 80 mph | 22.09 | 20.04 | 2.05 |
| 90 mph | 30.14 | 26.79 | 3.35 |
| 100 mph | 42.51 | 36.65 | 5.86 |
Under the skin
| Specification | US Impala | Canadian Impala |
|---|---|---|
| Sales code | 1BL69 | 1BL69 |
| Engine | 350 V8, 5.7 L | 350 V8, 5.7 L |
| Carburettor | 4-barrel | 4-barrel |
| Exhaust | single | single |
| Horsepower (SAE net) | 155 @ 3,600 rpm | 165 @ 4,000 rpm |
| Torque (lb-ft) | 265 @ 1,600 rpm | 260 @ 2,000 rpm |
| Compression | 8.2:1 | 8.2:1 |
| Transmission | 700R4 (overdrive, lock-up converter) | 350C (lock-up converter, no overdrive) |
| Axle ratio | 3.08 | 3.08 |
| Steering | power, integral, recirculating ball nut | power, integral, recirculating ball nut |
| Front suspension | independent, SLA, coil springs | independent, SLA, coil springs |
| Rear suspension | link type, 2 upper and 2 lower, coil springs | link type, 2 upper and 2 lower, coil springs |
| Brakes (swept area, sq in) | disc 273.0 / drum 138.2 | disc 237.0 / drum 138.2 |
| Tyres | P225/70R15 | P225/70R15 |
| Length / wheelbase (in) | 212.2 / 116.0 | 212.2 / 116.0 |
| Height (in) | 56.4 | 56.4 |
| Turning circle (ft) | 38.7 | 38.7 |
| Test weight (lb) | 3,993 | 3,839 |
| Test weight per horsepower (lb) | 25.8 | 23.3 |
| Rear leg room (in) | 39.1 | 39.1 |
| Interior / trunk volume (cu ft) | 110.3 / 20.9 | 110.3 / 20.9 |
Run by run
US Impala: the four acceleration runs (9:48 a.m., 52 °F, wind 8 mph from 320°)
| Seconds | Run 1 | Run 2 | Run 3 | Run 4 | Average |
|---|---|---|---|---|---|
| 0–60 | 11.15 | 11.74 | 11.83 | 11.96 | 11.67 |
| 0–80 | 20.88 | 23.03 | 21.67 | 22.78 | 22.09 |
| 0–100 | 38.44 | 46.40 | 40.35 | 44.85 | 42.51 |
Canadian Impala: the four acceleration runs (4:30 p.m., 62 °F, wind 8 mph from 330°)
| Seconds | Run 1 | Run 2 | Run 3 | Run 4 | Average |
|---|---|---|---|---|---|
| 0–60 | 10.72 | 10.91 | 11.10 | 11.39 | 11.03 |
| 0–80 | 19.36 | 20.01 | 19.82 | 20.95 | 20.04 |
| 0–100 | 37.21 | 35.66 | 36.67 | 37.06 | 36.65 |
The Canadian Impala’s four runs to 100 mph were within 1.55 seconds of each other. The US Impala’s were 7.96 seconds apart: its second and fourth runs were 4.5 to 8.0 seconds slower than its first and third. The book runs two in each direction to allow for wind, but does not say which runs went which way. The two cars started nearly seven hours apart, at 52 °F and 62 °F.
Around the road course
US Impala: all sixteen laps (average 1:32.21)
| Driver | Lap 1 | Lap 2 | Lap 3 | Lap 4 |
|---|---|---|---|---|
| Floate | 1:31.01 | 1:30.98 | 1:30.78 | 1:30.86 |
| Ring | 1:32.50 | 1:32.68 | 1:32.69 | 1:33.16 |
| Olsen | 1:33.09 | 1:32.82 | 1:33.11 | 1:33.35 |
| Steendam | 1:33.35 | 1:33.72 | 1:32.82 | 1:33.63 |
Canadian Impala: did not run the road course; the preface lists the Canadian cars as tested for acceleration and top speed.
Laps in grey are the four the book deleted for averaging (“Shaded areas indicate times deleted for overall averaging purposes”). On all 16 laps the US Impala averages 1:32.53 (computed here).
Braking in detail
| 60–0 mph stops | US Impala | Canadian Impala |
|---|---|---|
| Phase I: initial speed (mph) | 60.2 | not braked |
| Phase I: stopping distance (ft) | 167.6 | — |
| Phase I: rate (ft/s²) | 23.258 | — |
| Phase II: initial speed (mph) | 60.5 | — |
| Phase II: stopping distance (ft) | 169.8 | — |
| Phase II: rate (ft/s²) | 23.186 | — |
| Average rate (ft/s²) | 23.222 | — |
The book did not brake the Canadian cars “as their braking system is identical to their U.S. counterparts”. Its own data sheets print a front disc swept area of 273.0 square inches for the US Impala and 237.0 for the Canadian car, with the same 138.2 at the rear. The book does not comment on the difference.
Where they stand in the archive
- The Canadian Impala’s 36.65 seconds to 100 mph was quicker than every other car in the 1983 test except the Mustang (22.71 seconds).
- The US Impala 350 in the books either side: in 1982, 12.74 seconds to 60, 45.79 to 100 and 107.8 mph; in 1984, 10.30, 37.18 and 116.4 mph.
- Of the five scored cars in 1983, the US Impala’s 1:32.21 lap average was third, behind the Crown Victoria S (1:30.59) and the Malibu (1:32.13).
- Canadian-market cars appear again in the 1986 bulletin and the 1987 results held here, as Chevrolet Caprices.
0–100 mph across the test years
Each point is the 0–100 mph figure printed in that year’s source, as held in the archive’s test results: the full test book, or for 1985 the scoring sheet (the table names each). For 1985 the scoring sheet heads its column only “ACCEL sec”; the 1985 page reads it as the 0–100 time because the specification’s category is “0 – 100 Acceleration”. The 1978 and 1980 books print some averages to three decimals. The 1980 figure, the highest on the line, is from a re-run: the 1980 book says an extra spare tyre had been left in the Impala’s trunk, and Michigan re-ran its acceleration and top speed with tyres “slightly ‘flat spotted’” from the brake test (see the 1980 page); the book does not say whether either affected the times. The book eliminated the Impala from the full-size bid for failing the minimum acceleration requirements; it prints only the re-run figures. The tests ran on different days in different weather, so the line shows what each source printed, not a controlled comparison. The US line is every US-market Impala entry with the 350 engine, 1978 to 1985; the six-cylinder Impalas of 1983 and 1984, and the Impalas of 2000 to 2016, are in the test results but not plotted. A line does not say the car was the same from one year to the next. The Canadian Impala is the only Canadian-market Impala in the archive, so it is a single point. The break in the line is 1979, for which the archive has no results. Lower is quicker; the scale does not start at zero.
Every year in the chart
| Year | Source | Impala 350 (US market) | 0–100 (s) | Impala (Canadian) | 0–100 (s) |
|---|---|---|---|---|---|
| 1978 | book | Chevrolet Impala | 33.695 | — | |
| 1980 | book | Chevrolet Impala | 46.165 | — | |
| 1981 | book | Chevrolet Impala 350 | 39.98 | — | |
| 1982 | book | Chevrolet Impala 350 | 45.79 | — | |
| 1983 | book | Chevrolet Impala 350 | 42.51 | Chevrolet Impala (Canadian) | 36.65 |
| 1984 | book | Chevrolet Impala 350 | 37.18 | — | |
| 1985 | scoring sheet | Chevrolet Impala 350 | 42.24 | — |
What the numbers show
- On every acceleration figure the two cars share except 20 mph, where the US car was 0.03 seconds quicker, the Canadian Impala was ahead.
- The two cars’ data sheets match on every printed body dimension. They differ in rated horsepower, torque, transmission, test weight and front brake swept area, and the book gives no cause for the difference in times.
- The Canadian car’s top speed was cut short by what its run sheet calls “mechanical difficulties”, so the two top speeds are not compared.