Say bye to hypermiling at average 65+ mph?

You wish. Unfortunately, this rationalization for close following distances is a recipe for multi-vehicle chain reactions, for which I now have first-hand experience.

A month ago, the traffic's initial light braking suddenly turned to very hard braking, without any change of the already-lit brake lights in all lanes. I successfully slowed to a near stop without hitting anything. So did the driver behind me, though with essentially no margin. But the driver behind him failed, creating a 3 car pileup in the middle of the freeway. Had I been using slightly less following distance, it would have been a 4 car pileup.

I'm not a truck, but had I made any adjustment whatsoever for the car behind me, this would have been a 4 car pileup. Or more.

Be careful with those rationalizations for close following distances. Sometimes they work. Sometimes they don't. A thousands sighs of relief don't make up for the aggravations of a single failure.

 

I like the far right lane, cruising along with the big trucks but not following closely. The drivers for the most part are professional and courteous, and seem to prefer a safe, steady speed. In heavy traffic I will move one lane to the left. On a couple of recent round trips of 180 miles plus, and starting with a full tank, I averaged 65 and 66 mpg per the MFD display. Trucks here will hit a max of about 60, traffic permitting. If I've got one ahead of me and one behind, and none of us is crowding another, I'm perfectly happy at that speed, letting the speeding lane-jumpers take the risks of accidents and traffic citations. Leaving a space cushion does seem to annoy some car drivers, but it lets traffic merge from onramps, and at the same time cuts down on the constant speed adjustments I see in the other lanes.

 

In Ontario the safe legal distance to follow is also 2 seconds. However I find in any condition that has any type of traffic (pretty much everything in the city except night time) if you leave 2 sec at highway speed you will almost always have people behind you see that gap and take up that space. So if you insist of having a 2 sec gap you will continually be slowing down to increase the gap and continually be pi$$ing off everyone behind you causing them to fill that gap even quicker.

2 sec sounds good but in the real word the safe distance is balanceing your reaction time, braking distance, safety margins with the knowledge that certain things we do have a high chance of making other people drive a certain way. After an accident it's nice to know it wasn't your fault, but it's even better to have not gotten in that accident. I would say it's always safer to drive in an edge lane with less than 2 sec distance between you and the car infront of you than in a centre lane with exactly 2 sec and being boxed in left and right.

 

I've been quite impressed with the radar assisted cruise control that is an option on some models. Trying hard, I can only do a few mpg better than it, and it often reacts fractionally quicker than me to sudden drops in traffic speed. Overall, I think it is a serious contender for both safe and fuel efficient highway driving.

 

I've found it most useful on long trips where the elevation is dropping and with a tailwind, I get no-work mileage increases at higher speeds. In the opposite direction, I love it when I find a trucker going 50mph, rare but it happens. This is rolling hill terrain and sometimes high winds. (Your Mileage will Vary.)

 

I drive between Portland & Seattle all the time for work & in a truck most of the time. What I see, at a posted 70 limit, is that the right lane will see 55-60 mph, the middle lane will around 65 mph, and the left lane will see 70-75 mph. If traffic doesn't like your slower speed then they can pass, just stay in the right lane.

I've lived in many places & traffic will pass you without much thought. The speed limit is legally a maximum while minimum speeds on most interstate hwys are 20-25 mph lower in most states.

 

I did an experiment of drafting on the flats behind a bus for 30 miles, the mileage indicator never dropped below 60 and this was at 65+mph. It got to be pretty boring however looking at the back of the bus.

 

I was taught one second for each 10 mph. 2 seconds at 70 mph is too close.

 

(Sorry, I missed this one at the time.)

I was absolutely NOT rationalizing close following distances. In fact I was arguing the complete opposite: extra distance not only protects you from slamming into the car in front, but can protect you against someone slamming into the back of you.

I use longer buffering because I'm not just trying to avoid a collision, I'm trying to avoid hitting the brake at all.

 

Speeding is common on the freeways and the streets -- do the cops just not care? Owned my PiP for 1 week now and I've avoided 3 accidents.

Driving on the freeway, it's pretty common that I have to avoid at least 1 or 2 accidents because of some idiot. CHP WHERE ARE YOU!?

 

I remember reading about "SHM" which works above 60MPH or so. Basically, once you're up to speed, hold the HSI somewhere between 1/2 and 3/4.

 

Don't lose sight of the fact that you're getting better mileage in your Prius no matter how you drive than in what you WERE driving.

Playing the get-the-best-mpg-or-die-trying-in-my-Prius game is fun, but remember you are not the only person on the road.

Danger is in the eye of the beholder, I suppose, but think of this - how will you explain your death or dismemberment to that person in life that loves you the most and will be most devastated at your passing? Will they understand the importance of your getting that last three mpgs on the screen and the mayhem it caused?

Time for a reality check? You CAN get better mpgs by following more than 10 car lengths if the wind is with you. If it isn't, don't snuggle up to the car in front of you. Better to be smelling the roses than checking out the root system from up close.

 

Super Highway Mode(SHM) is when the ICE is off and the Prius is only using electrical power to move forward. Normally, when the HV Battery State of Charge(SoC) level is under 70% (6 bars and under), the ICE will go on at speeds over 46 mph in a 3rd generation Prius and at speeds over 43 mph in a 2nd generation Prius - so at these SoC level they represent the normal top speeds for SHM.

Under very unusally driving situations when the HV SoC level is at 75% level ( 7 bars and over), the Prius wont turn on the ICE and the cruise control is disable and the Prius tries to run entirely on the electric motors - during that time it is possible to go +60 mph with only the electric motors running (when this happens the Prius electric motors run very loud and are running very fast at this very special and infrequent top speed for SHM). This has happed to me only twice on my 2010 Prius III while going on extended downhill grades ( +10 percent grade downhill for longer than 1/4 of a mile at +60 mph) in the PA area (alt I40/I70) both times it has happend when I was on an extended interstate road trips. First time it happen to me I thought I broke something... The Prius basically doesn't like having its HV battery SoC levels to be over 70%...when the HV battery SoC levels drop to below 70% the Prius goes back to normal..

 

i havent been able to get SHM that high of MPG. typically high 40s low 50s. TPS of 18 or 19 with IGN at 21-22, RPMS somewhere around 1088. unless I am confusing that with SAHM? I am still trying to learn.

this car is amazing

 

The correct drafting technique is to stay 100 ft behind a truck (3 truck lengths) doing about 60 mph. The draft comes off the truck and around 100 ft behind it creates a vortice. If you drive in that vortice, wind resistance becomes zero. You save about 20% in fuel. You need an instant mile per gallon indicator. When you drive in the right spot you'll notice an instant change in mpg. You'll also notice a wind buffet. If you drive a little too close or far it won't work. You need to practice to get it right. If another car gets between you and the truck it won't work.

This is a technique often used in Europe. Trucks usually drive a steady 50 mph over there.

 

I don't try to "hyper mile" in my driving. I just use common sense driving to get the best mpg's. Stick in the righthand lane when ever possible. Anticipate traffic and road conditions. Even in the harsh DC area traffic I was able to get 58mpg on one of my last tankfuls.

 

You are hypermiling, according to Uncle Wayne's definition. You don't have to adopt the entire menu of methods, or even most of it, in order to qualify.

This is still unsafely and illegally close. The legal minimum in my state is 120 feet, the Two Second Rule demands 176 feet, and I prefer 300-500 feet.

No, that is Stealth or Warp Stealth, depending on whether the ICE is halted or spinning without fuel.

SHM was first discovered on the Honda Civic Hybrid (HCH), and is very definitely a fuel burning mode, albeit a very efficient condition. Wayne, Tarabell, and Jud made considerable use of this mode to push the HCH to 68+ mpg on their 48 state tour. Over at CleanMPG.com, you can get the ScanGauge IGN and TPS readings under which SHM occurs for the HCH, PriusII, and PriusIII. These readings cannot happen with electric-only propulsion.

PS: For Wayne's descriptions in PriusIII, see: 2010 Prius-III P&G, SHM and WS FE techniques rehashed, defined and refined

 

Well, I suggest you come drive in Los Angeles.

 

Not a chance. There is a reason SoCal drivers have bad reputations elsewhere.

I'd rather stay up here where approximately every twelfth licensed driver also has a concealed pistol license. Drivers are much less ill tempered, even with the drug mules barreling through on I-5 for their delivery routes between CA and BC.

 

NO, just the just the way I have tried to drive in these many years of driving. The only difference is seeing the results finally having an onboard computer in my car to make a difference.