I lol'ed.

 

i got 38.9 mpg at about 50 mph average today on the way to work. did nothing differently than normal other than let off the gas when a light turned red, and coast to the light instead of keep accelerating then hit the brakes. i figured it would be slightly better mileage, but ****, almost 40mpg especially considering it was stop and go is damn impressive.

 

with my stage 2, xtc intake and gmpp exhaust i get 26-28mpg city, i dont beat on it too much

 

I've got a 2.4 5-speed, and if I'm enthusiastic with my right foot I'm averaging 23 or so, so I'd expect 19-20 doing the same with a slushbox.

 

that is awesome ive been doing **** like this all the time lately.

 

...the DIC is more accurate then your "hand" calc. There are to many variables when you fill up your car and do the miles/gal. math for it to be more accurate then the computer monitoring the actual amount of fuel flow through the injectors

 

what variables exactly would somehow change the simple math of how many miles driven divided by how much gas was actually used from the tank?

 

do you know precisely how many gallons, down the the ounce were put in the car? probably not. that leaves room for error. there's your half a gallon also, suppose they put a tad more than the 13 gallon fillup, or a tad less. unless you are taking off your gas tank, dumping it out, and measuring, there's no way it's 100% accurate every single time. close, yes, but not 100%

 

Resetting the mpg meter, and doing my own math for nearly a year now, I found the meter is usually reading 2 mpg more than my own math at the pump. (27 on math, 29 on meter) Secondly, the whole reason this started was b/c of the Mythbusters where they confirmed the myth that you get better milage with the windows down than the a/c on.(bearing in mind it was two Explorers they did it in)

The a/c in my driving takes about 3 mpg off of the life of the tank. Even at speeds over 75, just cracking the windows open is better. All the way open though, and there's too much drag to tell the difference from what I saw. Also ticked at yahoo.com b/c they said differently on the front page today, debunking my research. I'd think they used a V8 when saying that, but then that contradicts what Mythbusters did.

 

yea but do you top off. that will change things too. the reason the pump shuts off is the pressure in your filler necjk tells it to. so sometime it will let more in than other times. it does this so that you can maintain a vaccum in the tank so the pump can suck fuel. so its never really right. this goes along with what reign and 420 were saying.

 

Gas also expands/contracts depending on ambient temperature.

 

i get 21.3 close enough...

 

man thats kinda crappy. im gettin 18-22 in my dodge nitro r/t wit a 4.0 liter

 

the definition of "city" driving could very greatly...

 

^agree.....your mileage would be different from mine....i deliver zza's so im constantly starting and stoping and i live in a decent size city so their are tons of lights and stop signs etc etc.....i get about 19.5 when im babying it

 

true. traffic n **** i dont got many stoplights or traffic jams in my so called city lol

 

14mpg in city and 19 in the free way, turbo

 

i got 28 all city. i never go on the highway. my cars lucky to drive on a highway for more then 15min in every 2 weeks.

 

The DIC is never going to be closer than "doing the math". The DIC is an average that is easily thrown off. If you sit there and don't move for a minute it puts 0mpg into the average. If you know anything about averages when 0 is added in even for a short time it really throws the number off and it will be lower than it should be. I find that the dic is a decent guide but it will always read a bit low due to this factor.

The most accurate way to get the mileage over the entire tank is to calculate it based on the fuel you just replaced. If you put in 12 gallons to fill it up and you drove 300 miles on the 12 gallons you just replaced then you got exactly 25mpg. A gas pump kicks off when it detects back pressure in the filler neck. As long as the pump is properly maintained they should all kick off at about the same point (or use the same pump each time if you wish). If it shuts off and there are a few ounces different it won't make a MEASURABLE difference in MPG. Who cares if there is a .001 change in mpg because of the pump not putting in that last few oz the last one did? So yes it is very accurate to the whole tank method.



Now as far as the mileage my 2.4 gets. Usualy 25mpg with about 90% city driving. The worst I got was around 22 in the dead of winter for all my city driving.

I just did a trip to Chicago and we did 32.5mpg on my best tank. I was running 71 mph on cruise pretty much the entire way. On this trip the DIC was pretty much spot on since there was no stopping.

You guys must really get on it alot to get such low numbers

 

crappy?? your only getting .7 more than me....

I constantly start and stop with tons of lights and stop signs. And let me tell you... Staten Island has a serious serious traffic problem.... it's NOT a fun place to drive as you might think it is. It's NOT uncrowded!

 

With a 4 litre motor.

 

ok..... but everyone else is getting just around the same or less (like your supposed to) so I dunno what your laughing about....

 

But wouldn't the results be the same? You figure the zeros when you are sitting still would bring the average down but isn't it for a good reason because you aren't going anywhere? Or if you did it by calculating it yourself and just sat there idling for a while, this would be reflected in your results too anyway wouldn't it?

 

i don't usually idle unless at a light so it's pretty accurate for me

 

I average at 29-31 mpg and I do half city half highway as well. Most of that is being pretty spirited on the pedal. Maybe I don't push the car as hard as others.