Highway driving, great MPG

[md13ffhguy]

I'm not opposed to "keeping up with the flow of traffic" on single-lane roads, within reason, of course. This is, unless you're expecting me to go more than 5-10 MPH over the posted limit. I feel like I'm a safer driver many times over since purchasing this car.

[ptjones]

Perfect recipe for a traffic jam on I-75/85 in Atlanta:

Tailgating a big truck only 50-100 feet back at 70 MPH while watching your speed and EV gauges. :drool:

 

I can't say what I really think of that because I'm on probation.

 

But I DO just LOVE people that allow their speed to vary by 10 MPH on the freeway.......no matter what lane their are in..........NOT.

That is funny, Truckers do it all time. If you are following a trucker how are you impeding traffic? I guess some people just like to complain. :)

 

Paul

[jeff_h]

That is funny, Truckers do it all time. If you are following a trucker how are you impeding traffic? I guess some people just like to complain. :)

 

Paul

 

I found a clip of Paul in the fast food line, drafting behind the guy in front.

[acdii]

To reiterate what Paul is saying, you can draft SAFELY behind a semi. Drafting has become a misconception to many, meaning they think drafting a semi has you 2 feet off the back end, which is really not the case. Follow a 2 second rule, and you are still drafting off a semi, especially a low loaded flatbed. The ACC setting at 1 bar puts you right at the safe distance, and works perfectly for "drafting". Y'all think we are out there driving Nascar style when we talk about drafting.

 

When I took the T to Florida I drafted several different vehicles in this manner, the best I found are motorhomes dragging a car. They really cut down on the head wind and smooth the airflow. Trick to follow when following a van, if you feel the car being buffeted, back off until is stops and maintain that distance, you are in the trucks slipstream at that point and in the safe zone, if you get closer you can get inside the buffet zone, but now you are in the kill zone, where you are not safe, and the driver cannot see you.

 

Just remember trucks cant stop as quick as the car(and the FFH can stop extremely quick in a panic stop, I know, I tried it the other day, hole S**T did it stop fast!), so as long as you are paying attention, and brake when you see the truck hit theirs, even if the trucker panic stops you still have enough room to stop safely provided you follow the correct distance of 2 seconds. Driving up another cars backside is more dangerous than drafting a semi, if a car stops fast, you will have a much higher chance of hitting them than hitting a truck.

[Easy Rider]

For me, that includes not using Eco CC but instead maintaining a constant speed whenever traffic conditions allow.

Well that is a whole DIFFERENT situation.

I like the Eco Cruise.

I don't think it allows much of an increased speed spread but just reacts less abruptly, especially when the spread is large for some reason.

I use it all the time and don't see that it creates a problem.

 

Having said that........I do manually accelerate when I notice that Adaptive Cruise has slowed me down more than 5 MPH below the speed limit and I pull out to pass the slow poke ahead. If you let ECO Cruise take care of that, it takes what seems like FOREVER.

[Easy Rider]

That is funny, Truckers do it all time. If you are following a trucker how are you impeding traffic? I guess some people just like to complain. :)

 

Paul

It's not funny at all.

Following too close is one of the major causes of "accidents" on the Interstates......especially in places like Atlanta and Chicago and St. Louis.....etc.

The traffic impeding comes in when you rear-end the car ahead and the traffic stops while they clean up your mess.

It happens almost every day in Atlanta; sometimes several times.

[Easy Rider]

Just remember trucks cant stop as quick as the car

 

Apparently you have never seen a demonstation of "reaction time" braking delay........or seen the short skid marks from a car that rear-ends a truck when a panic stop occurred.

 

At a 2 second interval, the average reaction time takes up half of that. If you are distracted even a teeny-tiny bit, the whole 2 seconds can elapse before you even touch the brake.

 

And when you are behind a big truck, your ability to see what is coming up in front a few cars down the road goes to ZERO.

 

Do you know anybody in Law Enforcement ? Ask them what they are taught in driving school about safe following intervals and big trucks.

[ptjones]

One to two Semi lengths isn't that close for me and yet I bet you would have no problem cutting in front of me when I'm drafting, it happens all the time. BTW I'm skinny, LOL Unfortunately this forum doesn't seem to be interested in improving MPG's anymore and picks on anyone that is. No point wasting anymore time here.

 

Paul

[GrySql]

Apparently you have never seen a demonstation of "reaction time" braking delay........or seen the short skid marks from a car that rear-ends a truck when a panic stop occurred.

 

At a 2 second interval, the average reaction time takes up half of that. If you are distracted even a teeny-tiny bit, the whole 2 seconds can elapse before you even touch the brake.

 

And when you are behind a big truck, your ability to see what is coming up in front a few cars down the road goes to ZERO.

 

Do you know anybody in Law Enforcement ? Ask them what they are taught in driving school about safe following intervals and big trucks.

Could you provide some resources (facts) that confirm what you are saying? We would appreciate being enlightened, but need some assurance that it's accurate.

 

I include your own quote below because it certainly is the way I feel too.

"Second or tenth hand "information" posted by someone I don't know just doesn't impress me though, because it usually is inaccurate for one reason or another."

[Easy Rider]

Could you provide some resources (facts) that confirm what you are saying? We would appreciate being enlightened, but need some assurance that it's accurate.

 

I did a google search.......which anybody can also do if they want to find information.......about most anything.

This was the first match on the list:

http://www.webpages.uidaho.edu/niatt_labmanual/chapters/geometricdesign/theoryandconcepts/BrakeReactionTime.htm

And this is the first paragraph:

"Brake Reaction Time

The brake reaction time is the amount of time that elapses between the recognition of an object or hazard in the roadway and the application of the brakes. The length of the brake reaction time varies widely between individual drivers. An alert driver may react in less than 1 second, while other drivers may require up to 3.5 seconds. "

 

If you are "one of those other drivers".......which of course NOBODY will admit to being.......and you are going 70 MPH and you are only 2 seconds behind a big truck when he panic brakes.......you are about 1.5 seconds into........DEAD. :drool:

 

I hope that's good enough because I am not going to spend anymore time doing something that you can do yourself.

 

Cheers.

Edited April 10, 2015 by Easy Rider

[Texasota]

Post #20 advocates drafting 50-100 feet behind a semi at 65 MPH (a little faster downhill and a little slower uphill). At 65 MPH you are traveling at 95.3 feet/second. That does not allow for much reaction time when 50 feet behind the semi.

 

I recently sat in a traffic jam on I-75 (south Florida) for an hour and 45 minutes because of a traffic accident but I don't know what the cause of the accident was. Multiple people died.

Edited April 10, 2015 by Texasota

[acdii]

So you are saying this is too close? It is more than a full semi length behind.

 

[acdii]

Here is ACC at 1 bar.

 

[md13ffhguy]

@70, and with the apparent need for wipers on, I'd say that looks a little close... especially while taking pictures...

[Easy Rider]

For long term travel, MUCH too close.......especially when you have extra "gadgets" to distract you.

 

Looks less than 2 seconds to me.

 

4 seconds is the most recent recommendation.

 

I'm not saying this to be argumentative; I'm saying it because it is important to your continued health.

 

I've seen and participated in accident clean up where the car ran under the back of a semi.

I don't ever want to do that again.

[Texasota]

Hard to know what your distance is in the photos but it looks like it is significanty greater than the 50 feet (especially in the first photo) that was advocated earlier. After some googling the average semi length appears to be around 70-80 feet.

 

But, at your speed of 70 MPH you are traveling 102.6 feet/second and with a 50 foot separation distance you would be practicing a .49 second rule instead of a 2 second rule.

Edited April 13, 2015 by Texasota

[md13ffhguy]

Here is ACC at 1 bar.

 

According to the manual, at a set speed of 62 MPH, 1 bar equals a 1 second gap. 2 bars is 1.4 seconds and 3 bars is 1.8 seconds. Personally, I choose either 3 or 4 at highway speeds, and reserve 1 and 2 for much slower situations.

[hybridbear]

According to the manual, at a set speed of 62 MPH, 1 bar equals a 1 second gap. 2 bars is 1.4 seconds and 3 bars is 1.8 seconds. Personally, I choose either 3 or 4 at highway speeds, and reserve 1 and 2 for much slower situations.

I do too. I don't like using anything less than 4 bars on the freeway. 4 bars is still less than 3 seconds at >62 MPH which is too close for my comfort.

 

The Chevy Volt's Adaptive Cruise Control allows you to set your following distance in seconds. I wish our cars could do that. You can set your following distance as high as 4+ seconds IIRC. I drove a Volt the other day with a friend who's looking at one and while we didn't have much chance to test the ACC, it looked like a much more advance system than what our cars offer.

 

I also agree about the reaction time issue. That's why a minimum following distance of 3 seconds is recommended, 4+ in rain/snow/etc. I still find it shocking that Ford's ACC system allows/encourages drivers to follow so closely. When we're doing long highway drives and are coming up on someone slow in our lane I try to always change lanes before the ACC starts slowing me down. If I feel the ACC slowing me down I know I am getting too close.

[acdii]

It is one and a half semi lengths at 2 bars. It is much farther back than majority of people I see driving out there, I have one picture with one person no further back than a half car length going by me at 80MPH. The ACC will slow you down quickly too as it happened to me this trip when a car cut me off just as traffic slowed down fast. Unless the truck in front hits a brick wall, I would be able to stop safely at that distance.

[CCalvinN]

I think good points have been made both for and against driving 'close' to somebody. I think the main pull away point is that the closer you drive to somebody the more 'aware' you have to be of your surroundings. Of the traffic, the weather, the way the person in front of you is driving. Accidents can happen at any distance if you are too distracted.

 

From my personal experience, the closer I drive to somebody the more aware I become and the more focused I get. For example while driving on the highway through Chicago I turn the radio down, and stop looking around at all the scenery. My eyes are almost entirely focused on the road ahead (not simply the car directly in front of me). That's because you're forced to drive close to people or be a hindrance to traffic. I'm sure others can back me up on this... two car lengths, no matter the speed, in that scenario is an invitation for someone to jump in front of you. In that case driving close is keeping me safe. I just have to pay the price there and focus all my attention on driving and not enjoying the drive.

 

On the other hand while driving the long open and sparely populated highways, I'll leave a FAR longer distance between me and the car in front of me. I want to enjoy the drive, the music, the scenery. If I chose to draft someone I would make that trade off... I'm now going to focus on driving more than enjoying the drive.

 

I haven't driven the FFH out on the open highways save for once (driving it from the dealer to my home upon purchase). The rest of my driving has been city or back country two lane highway (~60mph). I don't, however, think that drafting will be part of my driving philosophy. Yes, I could no doubt save some fuel, but I want to enjoy my driving more than I want to be efficient. While that's my choice, I won't knock anybody that chooses something different. So long as they're aware of their surroundings. If you're constantly checking your gauges to see just how efficient you are, then you could be as distracted as a teen texting somebody. In other words, a danger to yourself and others.

[Easy Rider]

I think the main pull away point is that the closer you drive to somebody the more 'aware' you have to be of your surroundings.

 

And I think the "main pull away point" is that too close is too close.

 

Being hyper aware is a short term thing; your attention soon wanders, whether you think it does or not.

 

And we are talking about being behind a semi-truck here.......where you can see virtually NOTHING about what is going on up ahead to help you gauge what might happen next........including but not limited to the truck running over something and kicking it up right into your windshield.

 

You are, of course, welcome to do what you want but all of the driving experts agree that you need about a 4 second interval to have any chance of stopping at all if the vehicle ahead makes a panic stop.

 

Just because people tailgate at 80 MPH every day doesn't make it right. Accidents happen every day because of it too. Sometimes people die.

[acdii]

Then again old farts have slow reaction times, so the further they are behind the better. makes it easier for the young hotshots to cut them off. :)

 

BTW, if you check out this picture, you will see what I saw the most, people driving way too close behind others. two in front left lane, and one right behind them, they were going at least 80+, so my driving distance is perfectly safe, and you can see I am 2 below the limit.

 

[jeff_h]

my driving distance is perfectly safe, and you can see I am 2 below the limit.

 

Except for the part about taking a picture of your dash at highway speed, hahahaha

[Easy Rider]

 

Except for the part about taking a picture of your dash at highway speed, hahahaha

And the fact that you are NEVER "perfectly safe" when going 80 MPH, unless maybe you are the only vehicle on the road.

 

Also the gauge of "perfectly safe" has absolutely nothing to do with what others are doing; it is not a relative thing.

[acdii]

I dont drove 80 MPH, I drive under 70 even when its 70, and my wife took the picture.