Horsepower And Mileage Problem Solved!!!!
07-13-2004, 04:26 PM
#151
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Shouldnt the grand touring package come with that? Ive got those (I have the grand touring package)...
u sure? The button is below the steeringwheel, towards the door...
u sure? The button is below the steeringwheel, towards the door...
07-14-2004, 10:04 AM
#152
RevBeeper
yup, you have. "Read the manual" (that will answer a lot of questions that come up). Hold the DSC button down for 8 seconds and if you get the "warning there are snakes following your car" (LOL...thats from the "Facts of Life").It will be in the middle of your tackometer.
07-15-2004, 03:04 AM
#153
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I think I got my "best" tank recently.
I filled up on Sunday. Drove 295 miles since, and refilled 12.9 gallons. That averages out to about 22.9mpg. 14,200mi on odometer.
Avg ambient temp 88ºF, A/C off, DSC/TCS on, windows down, sunroof open, ~200 freeway miles, ~100 street miles.
One thing that might have helped me was that I never exceeded 75mph on the highways, and purposely accelerated slowly.
My theory:
Having a K&N intake helps gauge how much throttle should be given to attain the best mpg. If you step on the gas pedal far enough to make the intake rumble while accelerating, a significantly greater amount of air gets sucked in. At that point the ecu is probably increasing the duty cycle of the injectors, which results in more gas being used through a shorter distance travelled. So, if you can drive in such a way as to prevent the intake from making that deep growl, your chances of getting better mpg are increased.
Sorry for rambling. It's late and I have no air conditioning. Plus its 90ºF around here and my fan is blowing hot air at me.
I filled up on Sunday. Drove 295 miles since, and refilled 12.9 gallons. That averages out to about 22.9mpg. 14,200mi on odometer.
Avg ambient temp 88ºF, A/C off, DSC/TCS on, windows down, sunroof open, ~200 freeway miles, ~100 street miles.
One thing that might have helped me was that I never exceeded 75mph on the highways, and purposely accelerated slowly.
My theory:
Having a K&N intake helps gauge how much throttle should be given to attain the best mpg. If you step on the gas pedal far enough to make the intake rumble while accelerating, a significantly greater amount of air gets sucked in. At that point the ecu is probably increasing the duty cycle of the injectors, which results in more gas being used through a shorter distance travelled. So, if you can drive in such a way as to prevent the intake from making that deep growl, your chances of getting better mpg are increased.
Sorry for rambling. It's late and I have no air conditioning. Plus its 90ºF around here and my fan is blowing hot air at me.
07-19-2004, 10:41 AM
#154
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Here's my first comparison... I'm not sure which of the 3 (or possibly all 3 combined) caused improvements but my MPG is hugely improved-
Before:
Original flash ('L')
93 Octane religiously
Never turned DSC or TC off
Full tank ~ 240-250 miles per tank with about 70% Highway driving
After
'M' Flash
89 Octane
DSC and TC off the entire tank
Full tank = 297 miles w/gas gauge buried below E ... again 70% Highway driving
I'm going to do the same thing on this tank without DSC/TC off to see if there is any decrease. Either way, it's kind of relieving to hit the 1/4 tank mark with 250 miles on the trip meter instead of the low fuel light :D
Before:
Original flash ('L')
93 Octane religiously
Never turned DSC or TC off
Full tank ~ 240-250 miles per tank with about 70% Highway driving
After
'M' Flash
89 Octane
DSC and TC off the entire tank
Full tank = 297 miles w/gas gauge buried below E ... again 70% Highway driving
I'm going to do the same thing on this tank without DSC/TC off to see if there is any decrease. Either way, it's kind of relieving to hit the 1/4 tank mark with 250 miles on the trip meter instead of the low fuel light :D
07-19-2004, 11:20 AM
#155
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Has anyone considered the gears you use most often? I do not thing DSC can really reduce your mileage since it only activates when your wheels are slipping.
Instead... I have found that for normal city use I tend to stay in the low gears (up to 4th) and rarely get up to 5th and 6th since the car has poor power at low revs... and high revs in 5th or 6th means you want to go to jail for speeding... keeping the car in its power sweetspot will make the drive more enjoyable but the gas performance will go down the sink...
just my 2 cents...
Instead... I have found that for normal city use I tend to stay in the low gears (up to 4th) and rarely get up to 5th and 6th since the car has poor power at low revs... and high revs in 5th or 6th means you want to go to jail for speeding... keeping the car in its power sweetspot will make the drive more enjoyable but the gas performance will go down the sink...
just my 2 cents...
07-19-2004, 04:06 PM
#156
RevBeeper
I found out just this weekend that changing gears at 3000 rpms and driving at 60 on the freeway you can get 300 miles and still have a quarter tank, but it was really boring doing that ( I sacraficed my driving fun) and I got cut off once, so I slapped it into 3rd and cherpt out on the suv driver. Basically even with one or two high reving beeps, you can still get 300 plus to the tank. To get good MPG you have to sacrafice the High Rev experiences.
07-19-2004, 04:19 PM
#157
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"One thing that might have helped me was that I never exceeded 75mph on the highways, and purposely accelerated slowly. "
I have a problem with the claim about accellerating slowly. I think it was Car and Driver that did an experiment with a car on two different tanks (or even more...I can't remember). Basically what they found was that it uses less fuel to accellerate quickly. Their rationale is that you achieve your cruising speed (which doesn't use nearly as much fuel as accelleration) more quickly and therefore spend less fuel per amount of time. They even had some cool graphs and stuff.
I haven't tried this out, and I'm just saying what I read, but it seems to make sense.
I have a problem with the claim about accellerating slowly. I think it was Car and Driver that did an experiment with a car on two different tanks (or even more...I can't remember). Basically what they found was that it uses less fuel to accellerate quickly. Their rationale is that you achieve your cruising speed (which doesn't use nearly as much fuel as accelleration) more quickly and therefore spend less fuel per amount of time. They even had some cool graphs and stuff.
I haven't tried this out, and I'm just saying what I read, but it seems to make sense.
07-19-2004, 04:36 PM
#158
Originally Posted by LucasET
"One thing that might have helped me was that I never exceeded 75mph on the highways, and purposely accelerated slowly. "
I have a problem with the claim about accellerating slowly. I think it was Car and Driver that did an experiment with a car on two different tanks (or even more...I can't remember). Basically what they found was that it uses less fuel to accellerate quickly. Their rationale is that you achieve your cruising speed (which doesn't use nearly as much fuel as accelleration) more quickly and therefore spend less fuel per amount of time. They even had some cool graphs and stuff.
I haven't tried this out, and I'm just saying what I read, but it seems to make sense.
I have a problem with the claim about accellerating slowly. I think it was Car and Driver that did an experiment with a car on two different tanks (or even more...I can't remember). Basically what they found was that it uses less fuel to accellerate quickly. Their rationale is that you achieve your cruising speed (which doesn't use nearly as much fuel as accelleration) more quickly and therefore spend less fuel per amount of time. They even had some cool graphs and stuff.
I haven't tried this out, and I'm just saying what I read, but it seems to make sense.
07-20-2004, 05:14 PM
#159
RevBeeper
ok here are some numbrs
with L flash
91 octain
290 miles
filled up 14.567 gallons
regular driving and the
Beeping revs
With L Flash
89 octain
300 miles
Filled up 14.885 Gallons
kept it mostly 70-65
Upgraded to M Flash
87 octain
290 miles
filled up 14.670
70-65 mostly
M Flash
91 octain
283 mile
filled up 13.600 Gallons
had some fun and
was late for work
beeped reved a
couple times
M Flash
91 octain
338.4 miles
filled up 14.481 Gallons
changed gears at 3000 rpm
cruising with a/c on at 60-62 MPH
DSC/TCS off, traveled 338.4 miles in
one weekend 75 % freeway 25 % city
I am currently Driving with DSC/TCS on with 91 octain a/c on and keeping it at 60-62 and shifting at 3000 rpms, let yall know the outcome on the next fill up.
Ry
with L flash
91 octain
290 miles
filled up 14.567 gallons
regular driving and the
Beeping revs
With L Flash
89 octain
300 miles
Filled up 14.885 Gallons
kept it mostly 70-65
Upgraded to M Flash
87 octain
290 miles
filled up 14.670
70-65 mostly
M Flash
91 octain
283 mile
filled up 13.600 Gallons
had some fun and
was late for work
beeped reved a
couple times
M Flash
91 octain
338.4 miles
filled up 14.481 Gallons
changed gears at 3000 rpm
cruising with a/c on at 60-62 MPH
DSC/TCS off, traveled 338.4 miles in
one weekend 75 % freeway 25 % city
I am currently Driving with DSC/TCS on with 91 octain a/c on and keeping it at 60-62 and shifting at 3000 rpms, let yall know the outcome on the next fill up.
Ry
07-25-2004, 12:23 PM
#162
RevBeeper
Ok, so far I am at 320 miles with the M Flash with DSC/TCS turned on, shifting at 3000rpm, driving at 60-62 (its hard doing that) and I have the gas warning light on. Gas warning light came on at 320. My conclusion is that DSC/TCS turned off has no Effect on your MPG, but it does have an effect on performance.
Thread is now DEAD, now I can have Fun Rev Beeping my 8 again
Originally Posted by TM45
I used my G-Timer today to test acceleration with DSC and TCS enabled/disabled. The car felt more lively with the system disabled, but I wanted to test it.
I measured 0-60 without revving the engine prior to launch and allowing no wheel spin at any time. The 0-60 times were slow as the engine really bogged off the line, but I was consistent in all four runs--two in each mode.
Enabled: 7.38
7.40
Disabled: 6.95
7.07
The car also seemed to coast better with the system disabled, so I tried another test. I have a big hill as approach my neighborhood and I usually coast down. I come over the crest about 30 and I usually hit a max of exactly 53 right before the hill levels out at the bottom. Same every day within a mile/hr. or two. With the system disabled the coasting speed was exactly 53--same as always.
It appears to me there is a measurable difference, though not in drag but in engine response. Four runs is not definitive, though there was consistency in the times within each mode. I will test again.
Just to keep the controversy alive.
I measured 0-60 without revving the engine prior to launch and allowing no wheel spin at any time. The 0-60 times were slow as the engine really bogged off the line, but I was consistent in all four runs--two in each mode.
Enabled: 7.38
7.40
Disabled: 6.95
7.07
The car also seemed to coast better with the system disabled, so I tried another test. I have a big hill as approach my neighborhood and I usually coast down. I come over the crest about 30 and I usually hit a max of exactly 53 right before the hill levels out at the bottom. Same every day within a mile/hr. or two. With the system disabled the coasting speed was exactly 53--same as always.
It appears to me there is a measurable difference, though not in drag but in engine response. Four runs is not definitive, though there was consistency in the times within each mode. I will test again.
Just to keep the controversy alive.
Thread is now DEAD, now I can have Fun Rev Beeping my 8 again
Last edited by NoPistonsHere; 07-25-2004 at 12:26 PM.
07-25-2004, 02:03 PM
#163
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There is no way to get 320 miles before your fuel light comes on. My experience has shown that light comes on at around 13 gallons used, or 2.8 left. This would mean you averaged 24 MPG on the first 13 gallons, and that is IMPOSSIBLE unless you set the cruise at 70 in 6th gear and drive 320 miles in one direction without slowing down or stopping.
Normal driving will include the startup time in the garage each day, stoplights, acceleration, etc. This will yield somewhere around 15 MPG. Once you average that in, you will be WAY under 24 MPG.
My fuel light comes on around 240 miles, and I think most other people's do as well.
B
S
Normal driving will include the startup time in the garage each day, stoplights, acceleration, etc. This will yield somewhere around 15 MPG. Once you average that in, you will be WAY under 24 MPG.
My fuel light comes on around 240 miles, and I think most other people's do as well.
B
S
07-25-2004, 02:31 PM
#164
The Turkish Delight
You know, after reading a lot of people's data based fuel economy findings the main conclusion people are coming up with is :
1. When you drive a lower revs, you get better gas milage.
2. When you drive slower (in 6th gear), you get better gas milage.
3. Higher flow through the engine uses more gas through the engine.
These should be elementary principles of engines, whether piston, rotary, or otherwise. (don't flame me, I'm just trying to make a point... read on)
Since fuel vs rpm vs speed curves aren't linear, is there any information out there that details ml/min of fuel use at different bands in the engine? As the 3 injectors come on line in sequence, there is greater ml/min flow.
If we can get fuel usage curves at different engine speeds (while the car is moving to take into account drag) we should be able to calculate the optimum rpm to run the engine speed at any given car speed.
Anyone (Mazda Engineers, this a plug for you) out there have this information? We can put an end to the arguments with real data.
1. When you drive a lower revs, you get better gas milage.
2. When you drive slower (in 6th gear), you get better gas milage.
3. Higher flow through the engine uses more gas through the engine.
These should be elementary principles of engines, whether piston, rotary, or otherwise. (don't flame me, I'm just trying to make a point... read on)
Since fuel vs rpm vs speed curves aren't linear, is there any information out there that details ml/min of fuel use at different bands in the engine? As the 3 injectors come on line in sequence, there is greater ml/min flow.
If we can get fuel usage curves at different engine speeds (while the car is moving to take into account drag) we should be able to calculate the optimum rpm to run the engine speed at any given car speed.
Anyone (Mazda Engineers, this a plug for you) out there have this information? We can put an end to the arguments with real data.
07-25-2004, 07:01 PM
#166
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I'm not trying to be argumentative here, but EPA testing shows 18/24 mpg, which means a normal "per-tank" average should be around 20 mpg. You can't get 25 mpg on the whole tank. Every second you sit idling, you are getting 0 mpg. Every time you accelerate, you are getting 5-8 mpg. Average that in, and the "per-tank" average takes a huge nosedive.
I drive 52 miles one-way every morning and every night, to and from work. 90 % of the drive is on the FL turnpike, cruise set at 70. 19-20 mpg every tank since I bought the car.
No offense, but I could skip resetting the odometer when I filled up too, then my car would show 400 when the light came on.....
I drive 52 miles one-way every morning and every night, to and from work. 90 % of the drive is on the FL turnpike, cruise set at 70. 19-20 mpg every tank since I bought the car.
No offense, but I could skip resetting the odometer when I filled up too, then my car would show 400 when the light came on.....
07-25-2004, 09:10 PM
#167
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I routinely get 285 miles on the odo before the gas light comes on, and average 21-22 mpg.
This is with spirited driving, taking it to redline at almost every time the ignition is turned on.
Could probably get the EPA mileage, but I didn't buy this car to drive it like a grandma.
This is with spirited driving, taking it to redline at almost every time the ignition is turned on.
Could probably get the EPA mileage, but I didn't buy this car to drive it like a grandma.
07-25-2004, 09:37 PM
#168
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Originally Posted by rxeightr
I routinely get 285 miles on the odo before the gas light comes on, and average 21-22 mpg.......
What do you guestimate your average driving highway/city percentages to be and what type of fuel do you use? I average 20 mpg 50/50 highway/city using Shell 87 octane. I don't drive like grandma nor do I drive like I stole it, but I'm mostly in the left lane.
rx8cited
07-25-2004, 10:15 PM
#170
Originally Posted by Tony Orlando
I'm not trying to be argumentative here, but EPA testing shows 18/24 mpg, which means a normal "per-tank" average should be around 20 mpg. You can't get 25 mpg on the whole tank. Every second you sit idling, you are getting 0 mpg. Every time you accelerate, you are getting 5-8 mpg. Average that in, and the "per-tank" average takes a huge nosedive.
I drive 52 miles one-way every morning and every night, to and from work. 90 % of the drive is on the FL turnpike, cruise set at 70. 19-20 mpg every tank since I bought the car.
No offense, but I could skip resetting the odometer when I filled up too, then my car would show 400 when the light came on.....
I drive 52 miles one-way every morning and every night, to and from work. 90 % of the drive is on the FL turnpike, cruise set at 70. 19-20 mpg every tank since I bought the car.
No offense, but I could skip resetting the odometer when I filled up too, then my car would show 400 when the light came on.....
There is a point 70-78mph where the AFR gets very rich I would stay out of that range.
Btw these numbers could be slightly off i haven't dynoed or plotted my A/F ratio in 6th gear only in 4th and 5th and there are slight differences in the M flash map per gears 4 through 6.
And you all wonder why i got a speeding ticket.
07-25-2004, 10:49 PM
#171
The Turkish Delight
Here's my mpg since ~2300 miles. I've got 10300 on it now. My average is 19.544 mpg over the last 30 fillups (all 87 octane gas). There are 6 long distance trips (22.4 mpg average) in there and 2 autocross races (where I got 17.3 mpg). From the graph, I put in upper and lower control limits 2 standard deviations away from my average. There is only one point out of this 2 SD control limit and that's one which has been high due to a long distance trip. (I think statistically +/-2.66 * the standard deviation is how to calculate upper and lower control limits.)
By the way, I have a mix of DCS on and off. I've turned it off when I remember, but sometimes, I didn't bother.
For zooming around town and having fun, 19.544 mpg is alright with me. I give my 8 plenty of excercise. Once they start getting out of control, I'll start to worry.
Anyone have those air/fuel ratio curves in 6th gear???
By the way, I have a mix of DCS on and off. I've turned it off when I remember, but sometimes, I didn't bother.
For zooming around town and having fun, 19.544 mpg is alright with me. I give my 8 plenty of excercise. Once they start getting out of control, I'll start to worry.
Anyone have those air/fuel ratio curves in 6th gear???
Last edited by legokcen; 07-25-2004 at 10:51 PM.
07-26-2004, 12:10 AM
#172
RevBeeper
Originally Posted by Tony Orlando
I'm not trying to be argumentative here, but EPA testing shows 18/24 mpg, which means a normal "per-tank" average should be around 20 mpg. You can't get 25 mpg on the whole tank. Every second you sit idling, you are getting 0 mpg. Every time you accelerate, you are getting 5-8 mpg. Average that in, and the "per-tank" average takes a huge nosedive.
I drive 52 miles one-way every morning and every night, to and from work. 90 % of the drive is on the FL turnpike, cruise set at 70. 19-20 mpg every tank since I bought the car.
No offense, but I could skip resetting the odometer when I filled up too, then my car would show 400 when the light came on.....
I drive 52 miles one-way every morning and every night, to and from work. 90 % of the drive is on the FL turnpike, cruise set at 70. 19-20 mpg every tank since I bought the car.
No offense, but I could skip resetting the odometer when I filled up too, then my car would show 400 when the light came on.....
Well Thats you, not me.
Maybe that Florida Humidity is weighing you down
Last edited by NoPistonsHere; 07-26-2004 at 12:30 AM.
07-26-2004, 12:50 AM
#173
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If you mash the pedal, your gas consumption will suck. I consistently get 11.5L/100km (20.5mpg) around town, no freeway driving. Extended trips, it improves to 24mpg. DSC is on all the time. I've had the car nearly a year (next week is the anniversary), and its got around 14,000 miles on the clock.
07-28-2004, 05:39 AM
#174
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I guess "good mileage" is subjective. Sunday I took the 8 out for some laps at Buttonwillow Raceway. The accelerator was pretty much on the floor whenever I wasn't braking or driving in the pits: 114.1 miles, 14.2 gallons = 8.04 mpg.
The mileage more than doubled on the trip back. Average speed about 90, DSC/TCS on, using gears freely, with the A/C full on in the 100+ degree heat: 278.8 miles, 14.4 gallons = 19.36 mpg.
Both of these figures seem reasonable to me, considering what the car was doing. Both were using Shell 89 octane unleaded. At the track, it saw 104-108 mph at the end of the longest acceleration area, and averaged 71-73 mph over the whole 3 mile circuit with many tight curves.
Turning off DSC/TCS has a noticeable effect on the track. The car is much more responsive in situations where one or more tires is sliding or spinning. There's one particular curve that was best taken by turning in hard and giving it full throttle just before the apex, causing a little back-end slide and powerful acceleration. With DSC/TCS on, the car would cut back its power and tweak the brakes in that situation. This showed itself in the max speed after this curve and before the next, about 78-79 with DSC/TCS on and 84-85 with it off.
I really don't think the engine develops more HP with the systems off, but I know without a doubt that the systems rob usable HP and tap the brakes in situations that are otherwise quite controllable - and best executed with power and a bit of wheelspin. The next test will be turning off only the DSC system, so the car can drift a bit but I won't get wheelspin on just one side.
I personally don't benefit from turning DSC/TCS off for street use. I don't start hard, and I don't often corner hard enough to bring them into play... the car is so fast that there are few places it's safe to corner that hard. I'd rather have the peace of mind of knowing they will help me through the unexpected maneuvers - like avoiding a deer suddenly bounding across the road.
The mileage more than doubled on the trip back. Average speed about 90, DSC/TCS on, using gears freely, with the A/C full on in the 100+ degree heat: 278.8 miles, 14.4 gallons = 19.36 mpg.
Both of these figures seem reasonable to me, considering what the car was doing. Both were using Shell 89 octane unleaded. At the track, it saw 104-108 mph at the end of the longest acceleration area, and averaged 71-73 mph over the whole 3 mile circuit with many tight curves.
Turning off DSC/TCS has a noticeable effect on the track. The car is much more responsive in situations where one or more tires is sliding or spinning. There's one particular curve that was best taken by turning in hard and giving it full throttle just before the apex, causing a little back-end slide and powerful acceleration. With DSC/TCS on, the car would cut back its power and tweak the brakes in that situation. This showed itself in the max speed after this curve and before the next, about 78-79 with DSC/TCS on and 84-85 with it off.
I really don't think the engine develops more HP with the systems off, but I know without a doubt that the systems rob usable HP and tap the brakes in situations that are otherwise quite controllable - and best executed with power and a bit of wheelspin. The next test will be turning off only the DSC system, so the car can drift a bit but I won't get wheelspin on just one side.
I personally don't benefit from turning DSC/TCS off for street use. I don't start hard, and I don't often corner hard enough to bring them into play... the car is so fast that there are few places it's safe to corner that hard. I'd rather have the peace of mind of knowing they will help me through the unexpected maneuvers - like avoiding a deer suddenly bounding across the road.
