600+ Miles Per Tank Club?

[ankit]

Originally Posted by DougFreeze

I'm a little confused at the theory that you have to use most of the fuel to get a good reading on MPG.?.
If I fill up, then drive 100 miles and then fill up again, take the gallons I just filled up with and divide by the 100 miles I just drove, how is that not as accurate as if I drove 500 miles and did the same thing?

No it is not the same thing. I think it is less accurate to take your readings like that because the errors of different pumps stopping at different amounts of fullness of the tank. This small amount of fuel difference lets say is .5 gallon. Well .5 of a gallon is a lot when you only filled up 2-3 gallons and it will show you an outrageous MPG. I got 45 MPG once when I filled up again after driving 15 miles. I was proud then realized that something was wrong. It is best when you go atleast half of a tank before filling up (speaking in terms of for checking fuel economy). When you fill up 10 or 15 gallons, that .5 of a gallon difference isn't too much anymore.

This is just something I read on another forum (on which the point is to get exceptional fuel economy). Hope it isn't too confusing.

[noz34me]

Originally Posted by DougFreeze

Theoretically, I could probably get 800 miles to the tank in my 2.5 if I ever really put it to the test.

What's our tank capacity? Isn't it 20 gallons? That would mean averaging over 40 mpg so you could pull in to fill up before you were completely empty.

I would like to know if this is possible, because I milk my car at times just to see what I can get and 38 mpg on the computer is about the best over several hundred miles. That usually means somewhere around 36.5 mpg in real life, and the computer is usually a little optimistic in my experience.

[2qk4um8]

It might be possible to get 40mpg if you fill up and drive only on highway for 800 miles, without traffic, no head wind, no steep slopes and nobody and nothing in the car. But thats nearly perfect environment for 800 miles. and on top you are risking to ran out of gas and maybe some damage to the engine because it will be sucking air in the end.

[DougFreeze]

Really, you guys haven't done this before?
You haven't put gas in the car, reset the computer and then immediately gotten on the freeway and then slowly cruised at about 55 MPH and watched the computer readings go from 67 MPG down to 59 MPG down to 44 MPG and then settle at about 42 MPG for as long as you can take driving that slow?
I do that all the time just to get that feeling of, "What the heck do I need a Prius for?"
Ya I know, that the computer is off by a couple Miles per gallon but on my car, it's not more than 2 MPG which is leaving me with about 40 MPG IF I were to continue driving at that speed and never leave the freeway.

I think it's fun.

[BlackD7]

I did a short trip of 250 miles 2 days ago I got 33mpg on the hwy doping cruising between 60 and 65. The read out was giving me 38 to 39 mpg. I believe I could have gotten better if I had stayed behind the trucks.

[OnTheAxis]

Originally Posted by BlackD7

I did a short trip of 250 miles 2 days ago I got 33mpg on the hwy doping cruising between 60 and 65. The read out was giving me 38 to 39 mpg. I believe I could have gotten better if I had stayed behind the trucks.

Slipstreaming is an effective way of increasing MPG, but dangerous b/c you have no visability of what is going on ahead of you.

And to make slipstreaming work, you need to tailgate the rear of the truck. I don't see it so often anymore, but semi's sometimes stay less than a car length apart.

So the lack of advanced warning, combined with tailgating, affords dramatically reduced time/space to react to a crisis. Nevermind the hypnotic effect of staring at the rear chassis of a semi for hundreds of miles and the stress of trying to stay alert throughout it all.

[DarthGanu]

Ouch! Slipstreaming behind trucks is also risky with small rocks and pebbles hitting your car's front fascia, hood and windshield.

Originally Posted by OnTheAxis

Slipstreaming is an effective way of increasing MPG, but dangerous b/c you have no visability of what is going on ahead of you.

And to make slipstreaming work, you need to tailgate the rear of the truck. I don't see it so often anymore, but semi's sometimes stay less than a car length apart.

So the lack of advanced warning, combined with tailgating, affords dramatically reduced time/space to react to a crisis. Nevermind the hypnotic effect of staring at the rear chassis of a semi for hundreds of miles and the stress of trying to stay alert throughout it all.

[ankit]

Originally Posted by OnTheAxis

Slipstreaming is an effective way of increasing MPG, but dangerous b/c you have no visability of what is going on ahead of you.

And to make slipstreaming work, you need to tailgate the rear of the truck. I don't see it so often anymore, but semi's sometimes stay less than a car length apart.

So the lack of advanced warning, combined with tailgating, affords dramatically reduced time/space to react to a crisis. Nevermind the hypnotic effect of staring at the rear chassis of a semi for hundreds of miles and the stress of trying to stay alert throughout it all.

You don't have to necessarily draft closely. You can go as far as 150 ft (atleast 100 ft) and still save fuel. Still not safe but you have more lean way.

[hotrodder]

Originally Posted by ankit

You don't have to necessarily draft closely. You can go as far as 150 ft (atleast 100 ft) and still save fuel. Still not safe but you have more lean way.

Actually, you are incorrect. To effectively "draft" a semi, ou have to be nose on bumper and you only get in increase of maybe a half MPG where as if youre 150 feet away, your MPG will decrease by a half MPG due to wind turbulance off the truck. Its been proven and you can look it up, mythe busters has gone through an entire episode of ways to increase MPG and hardly any of the theories people have are accurate such as this one. Another big misconception is that AC will decrease MPG, not ture, they proved that wrong as well.

If you only judge MPG on half a tank or 100 miles, the reading is HIGHLY innacurate. I dont know if you all notice it on yours but I can get 250-300 miles 100% stop go local traffic on half or more a tank, then bam it drops off insanely and I end up at 450 or so by the empty tank. I just calced my last tank. I put 19.01 gallons in it (tried draining it) and only got 451.8 miles out of her for an MPG reading of 23.76 MPG. Thats ridiculous, but its what NIssan advertises which is WHAT THESE CARS DO. Thats 100% local no highway driving, stop go street lights, stop signs, and me babying the cars throttle as much as I can, and the roads here are NOT level at all so theres up and down driving the whole time.

Now, I filled up last night and hit the highway, cruised up North a little over 70 miles cruise set at 60MPH, and then same coming home. I have a little more than 3/4 tank and Im at 152 total miles. In theory, I should be able to easily get 600+ if I kept doing that and only that, add local traffic or sitting at idle and theres no way. So, the guy claiming 600+ all city, YES I call BS and assume you dont know what youre doing. The ONLY way, mathmatically to get 700 miles (800 is just a ridiculous thought) is to jump on the highway seconds after filling up and driving with the cruise at 55 mph until the tank runs completely empty and the car coasts to its dead stop. Someone does that, then post it here, otherwise these guys that cant calculate correctly, need not post.

The problem is that someone else sees oh this guy is consistantly getting 35 mpg but im only getting 25, wy car is broken. How does that help anyone?? Wheres the benefit in fluffing up your MPG?? Does it make you sleep better at night? These cars have a 20 gallon tank, thats why we can go so much further than a lot of cars but bottom line is if these cars were 35 mpg, all the time, theyd advertise that until they were blue in the face but they dont because they cant unless driving conditions ar optimal. Fo us non highway goers, 24-29 is more accurate. I fill up MAYBE twice a month if not less often because I work 8 miles from my home so I dont drive all that much and its all local, those of you on the highways all the time, I agree with your better MPG but 40?? come on, be realistic.

One problem I see on the roads is that everyone complains that gas is so high but too many dont care to do anything about it on their end. If I had a gallon of gas for every jackass in a huge 9MPG SUV that flew by me after tailgating me for a mile until they got pissed off and flipped me off on the way by, I would never pay for gas again. IF you drive 90MPH on the highway and 15 MPH over the speed limit on the local roads, shut your damn mouth about gas being so high because you are the reason. I was cruise set at 60mph on the 55mph expressway last nigth getting passed like i was sitting still. Thats why gas is so high, because of the typical driver, not because of low amounts of fueal but because they KNOW we want it and will pay for it. I ams ooooo tired fo the gas is so high, MPG BS thats consuming soo many peoples lives these days.

[acs08]

Originally Posted by hotrodder

Actually, you are incorrect. To effectively "draft" a semi, ou have to be nose on bumper and you only get in increase of maybe a half MPG where as if youre 150 feet away, your MPG will decrease by a half MPG due to wind turbulance off the truck.

That's actually not true. If you watched the mythbusters episode where they tested this, they managed to increase fuel economy by 39% by maintaining a 10 ft distance from the big rig. But even at 100 ft, fuel economy was improved 11%. When the driver tried to maintain a 2 ft distance, he actually was only able to increase fuel economy by 29%. The theory they gave for this is he got a little antsy with the accelerator trying to maintain such a short gap.

[noz34me]

[quote=hotrodder;3538228]Another big misconception is that AC will decrease MPG, not ture, they proved that wrong as well. QUOTE]

In my experience, AC does decrease mpg; far more than lowering the windows. This is especially true under 60 mph, but I've found it is still more efficient to keep the AC off and windows down.

[2qk4um8]

Originally Posted by acs08

That's actually not true. If you watched the mythbusters episode where they tested this, they managed to increase fuel economy by 39% by maintaining a 10 ft distance from the big rig. But even at 100 ft, fuel economy was improved 11%. When the driver tried to maintain a 2 ft distance, he actually was only able to increase fuel economy by 29%. The theory they gave for this is he got a little antsy with the accelerator trying to maintain such a short gap.

link to above mentioned post" Mythbusters: drafting 10 feet behind a big rig will improve mileage 39 percent - AutoblogGreen

I agree with the article, that this is stupid and dangerous. I read it somewhere, that this is a one of main concerns for the "hypermilers" who all deem this as not one of their recommendations.

[ankit]

Originally Posted by hotrodder

Actually, you are incorrect. To effectively "draft" a semi, ou have to be nose on bumper and you only get in increase of maybe a half MPG where as if youre 150 feet away, your MPG will decrease by a half
MPG due to wind turbulance off the truck. Its been proven and you can look it up, mythe busters has gone through an entire episode of ways to increase MPG and hardly any of the theories people have are accurate such as this one. Another big misconception is that AC will decrease MPG, not ture, they proved that wrong as well.

I got my information after watching that episode. But I guess I was thinking 100 ft. I can definitely tell the difference from when the AC is on and off in the city judging from MPG, but not so much on the highway.

Originally Posted by hotrodder

The ONLY way, mathmatically to get 700 miles (800 is just a ridiculous thought) is to jump on the highway seconds after filling up and driving with the cruise at 55 mph until the tank runs completely empty and the car coasts to its dead stop. Someone does that, then post it here, otherwise these guys that cant calculate correctly, need not post.

Now I have belonged to a hypermiler forum for sometime, but do not goto the extremes that some others on there do (such as cutting off their engine while rolling). But I do like to drive more cautiously and do what I can to get better fuel economy. This would be safely getting behind a truck at a distance of 4-5 car lengths. This is only when I have another lane next to me as an exit route. I am a pretty observant driver after I got into an accident in which I got rear ended at other driver's fault. I do note brake lights of not only the car in front of me but in front of it also most times.

Originally Posted by hotrodder

The problem is that someone else sees oh this guy is consistantly getting 35 mpg but im only getting 25, wy car is broken. How does that help anyone?? Wheres the benefit in fluffing up your MPG?? Does it make you sleep better at night? Fo us non highway goers, 24-29 is more accurate. come on, be realistic.

I thank you for calling bs. I didn't want to rub some of the members here wrong, but I feel that it is close to impossible to get some of these numbers they put out there. I feel this way because I get nowhere near that 35+ MPG consistently along a whole tank and as I mentioned earlier I do hypermile (within limits). 700 miles per tank would mean that the person is getting almost 37 mpg ALONG THE WHOLE TANK assuming that they pull into the station with ~1 gallon remaining.

One problem I see on the roads is that everyone complains that gas is so high but too many dont care to do anything about it on their end. If I had a gallon of gas for every jackass in a huge 9MPG SUV that flew by me after tailgating me for a mile until they got pissed off and flipped me off on the way by, I would never pay for gas again. IF you drive 90MPH on the highway and 15 MPH over the speed limit on the local roads, shut your damn mouth about gas being so high because you are the reason. I was cruise set at 60mph on the 55mph expressway last nigth getting passed like i was sitting still. Thats why gas is so high, because of the typical driver, not because of low amounts of fueal but because they KNOW we want it and will pay for it. I ams ooooo tired fo the gas is so high, MPG BS thats consuming soo many peoples lives these days.

I'm afraid that only laws pushing fuel conservation or even higher gas prices will solve this problem.


__________________________________________________ ________________
With all of this being said, I hate how all hypermilers are put into one group of dangerous selfish people. Not all of us go 55 MPH on a road where the traffic flow is 70-75+ mph. Not all of us draft trucks at really closely. Actually even on that hypermiler forum that I frequent, the members shun those that do things like this and there are actually few hypermilers that do this from what I read.

[hotrodder]

Originally Posted by 2qk4um8

link to above mentioned post" Mythbusters: drafting 10 feet behind a big rig will improve mileage 39 percent - AutoblogGreen

I agree with the article, that this is stupid and dangerous. I read it somewhere, that this is a one of main concerns for the "hypermilers" who all deem this as not one of their recommendations.

I stand corrected, I must have misremembered what I heard. Thank you both for pulling the actual facts as I do not want ot be the guy who complains about peoples erroneous comments and then post my own. Lesson learned. I thought I remembered it differently but I was wrong. Does anyone have the exact info on the AC question they did as well? I can search but Im not able to at this moment . I want to make sure I recall that correctly as well.

[acs08]

Wish I had a link to the actual clip. They found that around 50 mph and faster, AC is more fuel efficient. Slower than 50, open windows would save you more gas.

MythBusters Episode 38: "MythBusters Revisited"