vince2 wrote: AltaRed wrote:
pmj wrote:It's my experience that most cars have engine sizes and capacities that are proportionate to the size and weight - and thus the power demand - of those cars. Relative to driving in hilly or mountainous country, the most significant deficiency of smaller cars in North America is not lack of power - it's older-style automatic gearboxes that limit one's ability to select the correct gear.
Tell that to the econoboxes that cannot maintain speed limit on the mountain grades out West or 130km/hr on 3-5% grades on the interstates. Tell that to the econoboxes that take upwards of 1km to pass another car at highway speeds on 2 lane highways. The damn things are accidents looking to happen. However, I do agree most vehicles today (other than econoboxes) DO have decent size/weight ratios.
Like pmj, I have never understood the insatiable need for massive amounts of torque in North America when the speed limit is (except for small stretches of highway) 120km/hr and proper attention to planning works well enough when the need to pass arises.
It is my perception after driving in Europe and Africa and North America that vast amounts of torque are often used in my neck of the woods to compensate for poor planning skills when driving. I was taught to drive smoothly, and the staccato manner of driving (either full acceleration or heavy braking) locally, seems to indicate a lack of appreciation of the mental aspects of driving.
Passing manoeuvres are excellent opportunities to exercise one's skills in mental differential calculus
. But right now I have a spreadsheet available - so here's a few assumptions with which to analyze the 1 km passing manoeuvre:
Both vehicles 5 metres long
Clear distance before passing = 5 lengths = 25 m
Length of passee = 5 m
Clear distance after passing = 5 lengths = 25 m
Distance to make-up = 55 m
Speed of passee = 120 km/h = 33.3 m/s
Speed of passer = 135 km/h = 37.5 m/s
Differential speed = 15 km/h = 4.2 m/s
Time to pass = 55/4.2 = 13.2 sec
Distance travelled by passee = 33.3 x 13.2 = 440 m
This calc makes no allowance for acceleration - it assumes that the passer is already travelling at 135 km/h. Is that a reasonable speed in a 100 / 110 / 120 km/h zone? And the five-vehicle length assumed for the lane change represents only 0.75 sec between vehicles - which seems kind of close?
Personally, this manoeuvre feels "tight". And yet it requires 440 m to complete it. Allowing 10 vehicle lengths (1.5 sec) for the lane-change increases the distance to 840 m. And dropping the passing speed to 130 km/h extends the distance to 1260 m.
ISTM that a significant cause of "slow" passing is poor driving skills. Using cruise control probably contributes - I rarely use mine, but when I do I notice that my driving technique changes from adjusting my speed to match other vehicles to "hoping" that I can fit between other cars without touching the gas or the brake
- which is a ridiculous way to drive