70mpg while driving 70mph

I was recently following a large truck at high speed and what I regard as a safe distance (I like 2 to 3 seconds, which is over 200 feet at 70 mph) when one of its rear tires blew. And I mean blew - there was a loud explosion and the tire literally disintegrated. One large fragment flew thirty feet in the air and travelled ten times as far, sailing over a power line and landing in a field. A couple of smaller fragments flew backwards and landed in the road ahead of me, but I was able to avoid them. I've also had a couple of lost loads land in front of me, including a stack of soft drink bottles that toppled backwards from a truck.

I'm not sure twenty or thirty feet is a safe distance and running your Prius into the back end of a truck will hurt a lot more than your gas mileage!

Mike

 

Three or four car-lengths is insanity. You know how there are these road accidents that cause tailbacks and delay you for hours, and you sit there thinking 'stupid drivers having accidents'.. well that's exactly how they happen. People driving too close too fast or doing something else that 'they're sure will be okay'

At 70mph you'd travel 30 feet in 300 milliseconds or thereabouts. That's not really long enough to be able to react safely. You'd probably have covered twice the amount of road you can actually see completely blind if you just so much as look in your mirrors.

It's not worth the risk for you and everyone else.

 

First off, Those run on sentences are absolutely painful to try and read. Secondly, i seriously doubt your numbers. While speeding is a problem and causes accidents, i'd think there are much more from other sources. doing a quick search (and i know, not everything on the web can be trusted) yeilded the following two sites:
http://www.legalmatch.com/law-library/arti...-accidents.html
http://www.lawcore.com/car-accident/statistics.html

which list massively different numbers: 98% due to distracted drivers (rubbernecking, cell phones, fatigue, adjusting the radio). Additionally, about 40% of car accident fatalities are caused by drunk driving. only 30% are caused by speeding. compare that with 33% for reckless driving (the numbers are not exclusive). I'd say following too closely falls into the "reckless driving" category.

A few years back i saw someone lose control of their vehicle and roll down the side of a hill on the highway. was he speeding? no. He was simply following behind a semi too closely. The semi drove over a deer he couldn't see, and when he could see it, he had jsut enough time to react and try to get around it, driving over it on one side, causing him to panic more.

moral of the story: Always, and i do mean always, give yourself time to react to anything that may happen in front of you. 20-30 feet at highway speeds isn't nearly enough time.

 

<div class='quotetop'>QUOTE(massimo @ Oct 9 2006, 10:20 AM) [snapback]330011[/snapback]</div>

Your reaction time might be better than someone else's (elderly or not), but that doesn't mean you'll have sufficient time to react.

It may take longer to stop a semi, but if some bozo cuts him off while you're changing stations, when he hits the brakes you could be hitting him ... especially if there's no place on the left or right to safely go. Worst case you wind up sandwiched between the semi and the car following you.

In my opinion, the reward of pushing more MPG out the car isn't worth the risk of an accident, injury or worse.
<div class='quotetop'>QUOTE(eagle33199 @ Oct 9 2006, 02:34 PM) [snapback]330130[/snapback]</div>

Go over here to ease your pain ----> http://priuschat.com/index.php?showtopic=25287&hl=

 

<div class='quotetop'>QUOTE(Proco @ Oct 9 2006, 01:54 PM) [snapback]330135[/snapback]</div>

Hmmmm..... Maybe i'll stop ignore FHOP if stuff like this is discussed! LOL

 

"I'm 25, therefore I'm invincible" -- typical. You'll get over it,
hopefully not the hard way.
.
On a long road trip last summer I did a little drafting [at a
relatively safe distance, but wasn't entirely comfy with it] on
the way out and then NO drafting on the way back. My MPG was
better on the return trip, because by giving myself a much larger
open cell to play in I could concentrate more on RPM control
instead of trying to always adapt on a shorter-term basis to how
far behind a truck I was, and that allowed the car to do its job
much better. If you're behind a truck at a nominally safe distance
you get a little wind-bucking effect, sure, but to really benefit
you'd have to stay tucked *way* in beyond any hope of safety and
visibility. 'Tain't worth it, end of story.
.
_H*

 

Yep. One of my areas of expertise is lightning safety, on which I also give advice and lectures. Many in my audiences are astonished to hear that over 80% of lightning casualties are male. It's more like 85% in the USA - but pretty much the same the world over. It's not that women are immune from lightning! The statistic is about the same for people bitten by snakes (or alligators) in western countries and for those rescued from the Grand Canyon with insufficient water.

The victims are almost exclusively males between the ages of 15 and 35. Great reaction times, no doubt, but bad judgement fueled by testosterone.

I am amazed I survived some of the dumb things I did when I was that age! But here I am, an old fart. lecturing youngsters who probably will pay as much attention to me as I did to my elders in the 1960s.

Mike

 

That's a sensible stopping distance, but I've never experienced slipstreaming/drafting at that distance. The other day I tried for a couple of seconds to see how close you'd have to be to get a tow, and it seemed to be like 20-30ft at 60mph.

Maybe you had a strong tailwind that day?

 

Being a pilot and having read up on fighter pilot performance:
Average reaction times for a FIGHTER PILOT (note excellent focus & reflexes).
0.25 seconds for the brain to recognize a threat that is seen.
0.25 seconds to get the foot or hand to the "switch"
0.25 seconds for the switch to start correcting the problem

This is slightly better then driver distance-reaction time charts from AAA. These chart the likelyhood of an accident based on TIME behind the vehicle in front. Picture a parabolic curve from zero, almost flat from 1 to 2 seconds.
Basically at 1.0 seconds behind you will not crash 90% of the time.
At 2.0 seconds behind you will not crash 99% of the time.

 

I drive 75 miles one way to work each day mostly on the Interstate and I can say that I, too, have noticed that drafting anything with a bigger profile than the Prius will increase your mileage. I try to stay at least 2 seconds behind them at highway speeds. That, I think, gives me enough time to react to a sudden speed change or sudden swerve from the vehicle in from of me. My MPG goes up anywhere from 5 to 15 MPG depending on what I'm drafting and of course the prevailing winds. My all time best was right at 60 MPG at 80 MPH drafting my favorite, a car carrying tractor trailer, (they create a lot of drag) with a good stiff wind at my back.
Most of the time I average between 48 and 51 MPG when drafting. Without drafting, it goes way down, around 42 MPG at 75 to 80 MPH.
I have noticed that some truckers don't like you drafting them. And they know you're there. I consider myself a curtious driver so I'll back way off if they slow down and speed up or keep changing lanes in light traffic.