I measured from 1/2----1/4 tank. I don't know which steps to take.sephiroth said:
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Real Bad Gas Mileage!
- Thread starter jimdogs
- Start date
The markings are irrelevant and inaccurate - it does not show 1/2, 1/4 atc accuirately. The only reasonably reliable way to measure mpg is to get a full tank of gas, reset trip computer, use up most of tank, refill tank (preferably at the same pump) and calculate mileage.mixmasterlove said:I measured from 1/2----1/4 tank. I don't know which steps to take.
On edit: By calculate the mileage, I of course mean divide the number of miles driven between the fillups by gallons pumped at the pump. Just wanted to clarify.
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I did a FULL tank---down to a 1/4 tank and got 235 miles on 3/4 of a tank =ing about 17.41 mpg is this good?? I have a AWD GT
The only way to accurately calculate mileage:
Fill you tank. Reset the trip odometer.
Drive.
When you get down to 1/4 of a tank go to the gas station and fill up. Look at the gas pump and write down how many gallons the car took. Then look at your trip odometer (while still at the gas station) and write down how many miles you drove (then reset trip odometer for next time). Divides miles driven by gallons used.
Any other way is just flat-out wrong. You cannot rely on the markings for 3/4, 1/2 and 1/4 of a tank, or getting down to when you fuel light comes on. If you want to do it accurately, the above method is the only way to do it. Anyone estimating how much is in their tank and using the "guessing" method is calculating wrong and not giving an accurate picture of the MPG this car is getting -- and it's also way too easy to WANT to estimate high.
I also uploaded a spread sheet for anyone who wants to track...
http://www.mazdas247.com/forum/showthread.php?t=123653975
Fill you tank. Reset the trip odometer.
Drive.
When you get down to 1/4 of a tank go to the gas station and fill up. Look at the gas pump and write down how many gallons the car took. Then look at your trip odometer (while still at the gas station) and write down how many miles you drove (then reset trip odometer for next time). Divides miles driven by gallons used.
Any other way is just flat-out wrong. You cannot rely on the markings for 3/4, 1/2 and 1/4 of a tank, or getting down to when you fuel light comes on. If you want to do it accurately, the above method is the only way to do it. Anyone estimating how much is in their tank and using the "guessing" method is calculating wrong and not giving an accurate picture of the MPG this car is getting -- and it's also way too easy to WANT to estimate high.
I also uploaded a spread sheet for anyone who wants to track...
http://www.mazdas247.com/forum/showthread.php?t=123653975
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So far I've been tracking my mileage...Tank 1: 19.1 MPG Tank 2: 19.6 MPG Tank 3: 21.6 MPG and a top off (1/2 tank) today: 23.4 MPG. I'm now at 1,080 miles and I can't say I've had a problem with gas mileage. I was Christmas shopping today running around to a couple different malls...today's highest rating I'd say came under 65% hwy and 35% city with lots of just going 5 MPH waiting for parking spots.
With these numbers...we've NEVER shut the climate control off and did some mountain driving yesterday...drove in the snow too! Thats a story for another thread though.
With these numbers...we've NEVER shut the climate control off and did some mountain driving yesterday...drove in the snow too! Thats a story for another thread though.
CXRabbit said:hehehe 16 is better than the 14 I've been getting -- I'm hoping for 16/17 this tank...
Just came back from a 400 miles trip and at 65 mph did about 18 mpg but at 75 mph did about 19.5 now talk about weird!! Have appointment with dealer tomorrow for other issues and oil change and will let them know how dissatisfied I am about the mpg and will bark loud if I do not see any improvements, after all they did advertise it at 22-24 mpg on the hwy even though it's an estimate, I would expect it to be around 20+ !! I do have 3,800 miles on her so she could be getting better over time. I'll ask them to flash my pcm.
(enguard)
1Sleepy93 said:I've found the best mileage comes around 75-80mph.
Drop the car off at the dealer and they told me that starting this September they'll be (all brands of vehicle) advertising a different EPA mileage sheet which more likely will drop the mpg 2-3 mpg. EPA has requested to adjust their estimated mpg to account for weather, area of the country and driver's skills i.e. speed, aggressiveness so our vehicle should drop to around 20-23 mpg on hwy. They also told me that I need to wait till after 10,000 miles to see the gas mileage "improvement"....we'll see (shocked)
I have calculated the mileage on my third tank (since Ive been logging) and with around 4000 miles on the odom, I averaged 14.1 mpg with mixed driving. So far since I started logging, Ive gotten: 12.4, 13.1, 14.1. These were all calculated the same way. The method I have been using is the resetting the odom and filling the tank. Then running it near empty and filling it up. Divide the gallons that went in from the odom reading...just in case anybody questions.
Xavier,
The way you're doing it is the ONLY accurate way to calculate. I am pretty convinced that a lot of people out there claiming to get 20 (or close to it) mpg around town are doing the guestimate way by looking at the gauge and guessing how much gas they used... especially the people who have less than 2000 miles on the car. I can't believe there are such huge discrepancies from one driver to the next. I KNOW how I drive, and I don't beat on the car, but I don't baby it either. I'm a pretty average driver who likes to have a little fun. I don't have the 5th-6th gear issue on the highway. If I'm getting low MPG around town (that I'm seeing improve as the car breaks in), I would imagine that should be fairly consistant for most people.
I've been keeping a log since the beginning and for the most part, am seeing improvements with each tank. So far it's been: 14.08, 13.89, 14.55, 16.65, 15.46 and the latest was 18.18 (with 1300 miles on the odometer). I do a LOT of around-town driving... probably 80-90% of the time during the school year it's like that. During the summertime it's a LOT more highway mileage (since I'm back and forth taking my daughter to camp 80 miles a day). It'll be interesting how I do then seeing as the engine should be substantially broken in as well.
Nash - you can't blame the dealer for the MPG on the sticker. That isn't done by them, it's done by the EPA. And they way they do it is pretty unrealistic to the real-world.
The way you're doing it is the ONLY accurate way to calculate. I am pretty convinced that a lot of people out there claiming to get 20 (or close to it) mpg around town are doing the guestimate way by looking at the gauge and guessing how much gas they used... especially the people who have less than 2000 miles on the car. I can't believe there are such huge discrepancies from one driver to the next. I KNOW how I drive, and I don't beat on the car, but I don't baby it either. I'm a pretty average driver who likes to have a little fun. I don't have the 5th-6th gear issue on the highway. If I'm getting low MPG around town (that I'm seeing improve as the car breaks in), I would imagine that should be fairly consistant for most people.
I've been keeping a log since the beginning and for the most part, am seeing improvements with each tank. So far it's been: 14.08, 13.89, 14.55, 16.65, 15.46 and the latest was 18.18 (with 1300 miles on the odometer). I do a LOT of around-town driving... probably 80-90% of the time during the school year it's like that. During the summertime it's a LOT more highway mileage (since I'm back and forth taking my daughter to camp 80 miles a day). It'll be interesting how I do then seeing as the engine should be substantially broken in as well.
Nash - you can't blame the dealer for the MPG on the sticker. That isn't done by them, it's done by the EPA. And they way they do it is pretty unrealistic to the real-world.
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CX7andMiata
Member
- :
- CX-7 AWD GT, Copper Red Mica with Tech. Package
With the A/C off (as much as I can make it) and driving around town I am getting about 20-21. With the climate control system in auto I get about 18 so something is definitely different when the climate control is not in auto...1Sleepy93 said:I've gotten 20-23mpg on several occasions and use miles divided by gallons to get my mpg. Those tanks where 70% or more freeway driving however. Average mpg with 70-80% around town is 19mpg.
1Sleepy93 said:I've found the best mileage comes around 75-80mph.
Then I doubt you drive at a consistent 60mph everywhere.
because of aerodynamics and in GENERAL...
The power required to overcome the aerodynamic drag is given by:
P sub d= F sub d * v = - .5 * rho * v^3 * A * C sub d
[Pd=Fd*v= -(1/2)pv^3ACd]
Note that the power needed to push an object through a fluid increases as the cube of the velocity. A car cruising on a highway at 50 mph (80 km/h) may require only 10 horsepower (7.5 kW) to overcome air drag, but that same car at 100 mph (160 km/h) requires 80 hp (60 kW). With a doubling of speed the drag (force) quadruples per the formula. Exerting four times the force over a fixed distance produces four times as much work. At twice the speed the work (resulting in displacement over a fixed distance) is done twice faster. Since power is the rate of doing work, four times a work in half the time requires eight times the power.
Best mileage comes where the power required curve (vs speed) meets the torque[work] (vs speed) curve. Best acceleration, and therefore best fuel efficiency comes at the torque[qork] peak, not horsepower[work over time]. Best power required is @ approaching 0 mph because of the above formula. We know the slope of the curve and we can get a torque vs mph graph at any competent dyno....
My (very) educated guess is the best gas mileage will come just before torque peak (2500 rpm IIRC) in 6th gear in a no wind condition. So what's that, like 60-65mph?
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CXRabbit said:Xavier,
The way you're doing it is the ONLY accurate way to calculate. I am pretty convinced that a lot of people out there claiming to get 20 (or close to it) mpg around town are doing the guestimate way by looking at the gauge and guessing how much gas they used... especially the people who have less than 2000 miles on the car. I can't believe there are such huge discrepancies from one driver to the next. I KNOW how I drive, and I don't beat on the car, but I don't baby it either. I'm a pretty average driver who likes to have a little fun. I don't have the 5th-6th gear issue on the highway. If I'm getting low MPG around town (that I'm seeing improve as the car breaks in), I would imagine that should be fairly consistant for most people.
I've been keeping a log since the beginning and for the most part, am seeing improvements with each tank. So far it's been: 14.08, 13.89, 14.55, 16.65, 15.46 and the latest was 18.18 (with 1300 miles on the odometer). I do a LOT of around-town driving... probably 80-90% of the time during the school year it's like that. During the summertime it's a LOT more highway mileage (since I'm back and forth taking my daughter to camp 80 miles a day). It'll be interesting how I do then seeing as the engine should be substantially broken in as well.
Nash - you can't blame the dealer for the MPG on the sticker. That isn't done by them, it's done by the EPA. And they way they do it is pretty unrealistic to the real-world.
Sorry about the confusion but I never blame the dealership except perhaps Mazda themselves for the EPA rating but as I stated earlier, the EPA are changing their ways starting this September. Also the dealership flash my PCM and TCM so next time I'm on the road, I'll check it out but I can already tell the performance was better. If you need the update done, let them know that you have hesitation btwn 60-70 mph and the transmission keeps going from 6th to 5th, back and forth.
cocoagyrl77
Member
- :
- Black CX-7 GT w/ Sand Interior
I am so late...
I know this is late but, True...true...
nate0123 said:quit buying SUVs if you want good gas mileage
I know this is late but, True...true...
Respectfully, my issue with the CX-7 is not that it gets "bad" gas mileage, rather that it is getting mileage significantly belowthe EPA rating. I'm aware that the EPA ratings are not "real world" numbers, however with previous vehicles I've owned I was able to get within 10-20% of the EPA numbers. I'm well aware that the CX-7 will never get the mileage of a Hybrid Civic, however if the EPA/Mazda say this thing can get 24mpg then I expect to get reasonably close (all things being equal).
I recently experimented with my CX-7 while doing a mix of city/highway driving (minimal inner city idling). I concentrated on keeping the RMP's down and not engaging the turbo (basically I drove like my grandmother). I actually recorded mileage higher than the EPA rating - not unexpected but I have no intention of driving like this in the future. However it was nice to know it could be done.
I am so late...
--------------------------------------------------------------------------------
Quote:
Originally Posted by nate0123
quit buying SUVs if you want good gas mileage
I know this is late but, True...true...
__________________
She is lovely...and I call her "Black Beauty"
I recently experimented with my CX-7 while doing a mix of city/highway driving (minimal inner city idling). I concentrated on keeping the RMP's down and not engaging the turbo (basically I drove like my grandmother). I actually recorded mileage higher than the EPA rating - not unexpected but I have no intention of driving like this in the future. However it was nice to know it could be done.
I am so late...
--------------------------------------------------------------------------------
Quote:
Originally Posted by nate0123
quit buying SUVs if you want good gas mileage
I know this is late but, True...true...
__________________
She is lovely...and I call her "Black Beauty"
Well, considering the EPA does indeed test all cars as if a grandmother were driving them, it's not at all surprising. With SOME vehicles there is going to be less discrepency when you drive hard vs. soft -- but in a turbo? There's going to be lots of room for variability. Trust me, I'd LOVE to be getting 24mpg, but it's never going to happen as long as I own this car and drive like I drive.
