Other vehicles I have driven cruise 70 mph at about 2,500-2,750 RPM, whereas my 3 at more like 3000 at 65-70 mph. And 75 mph is like 3500, its almost 4000 rpm if I go up to 80.. Does this seem a little high or is it normal for the 3?
Cristina
[quote author=Cristina link=topic=51301.msg817509#msg817509 date=1152682354]
Other vehicles I have driven cruise 70 mph at about 2,500-2,750 RPM, whereas my 3 at more like 3000 at 65-70 mph. And 75 mph is like 3500, its almost 4000 rpm if I go up to 80.. Does this seem a little high or is it normal for the 3?
[/quote]
Here is the calculation for the 5sp MTX
1 2 3 4 5
0 0.0 0.0 0.0 0.0 0.0
500 2.7 4.9 6.9 9.3 12.0
1000 5.5 9.8 13.8 18.7 24.0
1500 8.2 14.7 20.7 28.0 36.0
2000 10.9 19.7 27.6 37.3 47.9
2500 13.7 24.6 34.5 46.6 59.9
3000 16.4 29.5 41.4 56.0 71.9
3500 19.2 34.4 48.4 65.3 83.9
4000 21.9 39.3 55.3 74.6 95.9
4500 24.6 44.2 62.2 84.0 107.9
5000 27.4 49.1 69.1 93.3 119.9
5500 30.1 54.0 76.0 102.6 131.8
6000 32.8 59.0 82.9 111.9 143.8
6500 35.6 63.9 89.8 121.3 155.8
7000
redline 38.3 68.8 96.7 130.6 167.8
Sorry the grid gets all askew but it should be able to read right. The 5 speed is geared a little sportier than the ATX. These cars make power up top, not down low so the gearing reflects where the engine needs to be to accelerate at speed.
Hope this helps!
Other vehicles I have driven cruise 70 mph at about 2,500-2,750 RPM, whereas my 3 at more like 3000 at 65-70 mph. And 75 mph is like 3500, its almost 4000 rpm if I go up to 80.. Does this seem a little high or is it normal for the 3?
[/quote]
Here is the calculation for the 5sp MTX
1 2 3 4 5
0 0.0 0.0 0.0 0.0 0.0
500 2.7 4.9 6.9 9.3 12.0
1000 5.5 9.8 13.8 18.7 24.0
1500 8.2 14.7 20.7 28.0 36.0
2000 10.9 19.7 27.6 37.3 47.9
2500 13.7 24.6 34.5 46.6 59.9
3000 16.4 29.5 41.4 56.0 71.9
3500 19.2 34.4 48.4 65.3 83.9
4000 21.9 39.3 55.3 74.6 95.9
4500 24.6 44.2 62.2 84.0 107.9
5000 27.4 49.1 69.1 93.3 119.9
5500 30.1 54.0 76.0 102.6 131.8
6000 32.8 59.0 82.9 111.9 143.8
6500 35.6 63.9 89.8 121.3 155.8
7000
redline 38.3 68.8 96.7 130.6 167.8
Sorry the grid gets all askew but it should be able to read right. The 5 speed is geared a little sportier than the ATX. These cars make power up top, not down low so the gearing reflects where the engine needs to be to accelerate at speed.
Hope this helps!
[quote author=ViperKillerWannabe link=topic=51301.msg817623#msg817623 date=1152693146]
I *may* be reading that wrong, but the redline on my 3 is 6500. Your graph seems to be showing that quite a bit higher than that.
[/quote]
7k is "quite a bit"??? 6.5k is the redline on the gauge, 7k is rev limit.
I *may* be reading that wrong, but the redline on my 3 is 6500. Your graph seems to be showing that quite a bit higher than that.
[/quote]
7k is "quite a bit"??? 6.5k is the redline on the gauge, 7k is rev limit.
A few questions, are those numbers the mph corresponding to the RPMs. If so how come if the rev limiter is at 7K why does the top speed stop at 119.
Also when it comes to fuel milage i was checking the speed vs the RPMs and in 5th gear they all seem identical. So is speed and RPM not a good judgement of fuel. Does the car burn more gas at higher RPMs.
Example, which statement is more true
the car burns twice as much gas at 4000 RPMs than it does at 2000 RPMs
the car buns less than twice as much gas at 4000 RPMs than it does at 2000 RPMs
the car burns more than twice as much gas at 4000 RPMs than it does at 2000 RPMs.
This is considering cruising RPMs, no acceleration. Just driving on a flat grade and maintaing speed.
Also when it comes to fuel milage i was checking the speed vs the RPMs and in 5th gear they all seem identical. So is speed and RPM not a good judgement of fuel. Does the car burn more gas at higher RPMs.
Example, which statement is more true
the car burns twice as much gas at 4000 RPMs than it does at 2000 RPMs
the car buns less than twice as much gas at 4000 RPMs than it does at 2000 RPMs
the car burns more than twice as much gas at 4000 RPMs than it does at 2000 RPMs.
This is considering cruising RPMs, no acceleration. Just driving on a flat grade and maintaing speed.
[quote author=ewmatter link=topic=51301.msg818180#msg818180 date=1152722053]
it looks like 909 posted speeds for the speed3....155mph is the top speed for the speed3, not your everyday 3.
[/quote]
That chart is not a "Mazda 3 speed chart" It's a mathematical chart based on gear ratios and tire size. It just happens the input I used was the specs of the 3. We use charts like this when determining gearing changes, tire size changes, etc... The original post was asking if there was a problem with her 3 beacause it rev'd so high at highway speed. If your clutch is slipping it can be a problem but how do you know for sure? Easy, look at the chart. If your engine RPM doesn't match the mathematical answer then there is slippage somewhere. The chart does not imply the car goes 800 MPH, or that the engine revs to 8k freely. Please don't interpret it as such.
When you're in 1st gear and floor it, the rev limiter will kick in eventually preventing you from grenading the engine. This is an electrical kill to the spark. When you're in 4th and hit 118MPH and you're not at the ignition limiter, the top speed limiter kicks in and it kills fuel, these are 2 different limits, remember rev=spark and speed=fuel.
it looks like 909 posted speeds for the speed3....155mph is the top speed for the speed3, not your everyday 3.
[/quote]
That chart is not a "Mazda 3 speed chart" It's a mathematical chart based on gear ratios and tire size. It just happens the input I used was the specs of the 3. We use charts like this when determining gearing changes, tire size changes, etc... The original post was asking if there was a problem with her 3 beacause it rev'd so high at highway speed. If your clutch is slipping it can be a problem but how do you know for sure? Easy, look at the chart. If your engine RPM doesn't match the mathematical answer then there is slippage somewhere. The chart does not imply the car goes 800 MPH, or that the engine revs to 8k freely. Please don't interpret it as such.
When you're in 1st gear and floor it, the rev limiter will kick in eventually preventing you from grenading the engine. This is an electrical kill to the spark. When you're in 4th and hit 118MPH and you're not at the ignition limiter, the top speed limiter kicks in and it kills fuel, these are 2 different limits, remember rev=spark and speed=fuel.
[quote author=4cylDriver link=topic=51301.msg817680#msg817680 date=1152705833]
A few questions, are those numbers the mph corresponding to the RPMs. If so how come if the rev limiter is at 7K why does the top speed stop at 119.
Also when it comes to fuel milage i was checking the speed vs the RPMs and in 5th gear they all seem identical. So is speed and RPM not a good judgement of fuel. Does the car burn more gas at higher RPMs.
Example, which statement is more true
the car burns twice as much gas at 4000 RPMs than it does at 2000 RPMs
the car buns less than twice as much gas at 4000 RPMs than it does at 2000 RPMs
the car burns more than twice as much gas at 4000 RPMs than it does at 2000 RPMs.
This is considering cruising RPMs, no acceleration. Just driving on a flat grade and maintaing speed.
[/quote]
There is no statement there about efficiency in there. All internal combustion engines operate at different efficiency ratings at different RPM's. The efficiency does have alot to do with RPM, cam timing, throttle position, and load. Any answer to efficiency based solely on RPM would be completely innacurate at best.
Example: A car running at 1500RPM into a 20 MPH head wind, with 4 flat tires, and 4 passengers weighing 350lbs each would use the same amount of fuel as the same car running at 6000RPM on flat ground doing 110MPH with 1 150lb driver and no head wind. (this is all made up BS anyway so don't think I actually calculated this!!)
According to your question above and ignoring the variables the same car would use an equal amount of fuel running at 1500 RPM as it does at 6000 RPM.
A few questions, are those numbers the mph corresponding to the RPMs. If so how come if the rev limiter is at 7K why does the top speed stop at 119.
Also when it comes to fuel milage i was checking the speed vs the RPMs and in 5th gear they all seem identical. So is speed and RPM not a good judgement of fuel. Does the car burn more gas at higher RPMs.
Example, which statement is more true
the car burns twice as much gas at 4000 RPMs than it does at 2000 RPMs
the car buns less than twice as much gas at 4000 RPMs than it does at 2000 RPMs
the car burns more than twice as much gas at 4000 RPMs than it does at 2000 RPMs.
This is considering cruising RPMs, no acceleration. Just driving on a flat grade and maintaing speed.
[/quote]
There is no statement there about efficiency in there. All internal combustion engines operate at different efficiency ratings at different RPM's. The efficiency does have alot to do with RPM, cam timing, throttle position, and load. Any answer to efficiency based solely on RPM would be completely innacurate at best.
Example: A car running at 1500RPM into a 20 MPH head wind, with 4 flat tires, and 4 passengers weighing 350lbs each would use the same amount of fuel as the same car running at 6000RPM on flat ground doing 110MPH with 1 150lb driver and no head wind. (this is all made up BS anyway so don't think I actually calculated this!!)
According to your question above and ignoring the variables the same car would use an equal amount of fuel running at 1500 RPM as it does at 6000 RPM.
[quote author=Blazestorm link=topic=51301.msg821422#msg821422 date=1152821539]
Want to do a 4-speed automatic?
I want to see if I'm in the good spot.
I'm just above 3000rpm for 70mph... probably 3100... or 3200...
[/quote]
1 2 3 4
0 0.0 0.0 0.0 0.0
500 3.6 6.7 10.1 13.9
1000 7.2 13.5 20.2 27.8
1500 10.7 20.2 30.3 41.7
2000 14.3 26.9 40.3 55.6
2500 17.9 33.7 50.4 69.6
3000 21.5 40.4 60.5 83.5
3500 25.1 47.2 70.6 97.4
4000 28.7 53.9 80.7 111.3
4500 32.2 60.6 90.8 125.2
5000 35.8 67.4 100.9 139.1
5500 39.4 74.1 110.9 153.0
6000 43.0 80.8 121.0 166.9
6500 46.6 87.6 131.1 180.8
7000
redline 50.1 94.3 141.2 194.8
There it is, please dont anyone now tell me the 4AT won't do 194.8 MPH...
Keep in mind these are gear ratios assuming a direct connection and they don't account for the slippage of an ATX.
Want to do a 4-speed automatic?
I want to see if I'm in the good spot.
I'm just above 3000rpm for 70mph... probably 3100... or 3200...
[/quote]
1 2 3 4
0 0.0 0.0 0.0 0.0
500 3.6 6.7 10.1 13.9
1000 7.2 13.5 20.2 27.8
1500 10.7 20.2 30.3 41.7
2000 14.3 26.9 40.3 55.6
2500 17.9 33.7 50.4 69.6
3000 21.5 40.4 60.5 83.5
3500 25.1 47.2 70.6 97.4
4000 28.7 53.9 80.7 111.3
4500 32.2 60.6 90.8 125.2
5000 35.8 67.4 100.9 139.1
5500 39.4 74.1 110.9 153.0
6000 43.0 80.8 121.0 166.9
6500 46.6 87.6 131.1 180.8
7000
redline 50.1 94.3 141.2 194.8
There it is, please dont anyone now tell me the 4AT won't do 194.8 MPH...
Keep in mind these are gear ratios assuming a direct connection and they don't account for the slippage of an ATX.
[quote author=shabu link=topic=51301.msg824542#msg824542 date=1152926271]
are these numbers using 2.0 ratios? I recently took a long trip in my 2.3 AT and 4000 rpm in 4th is much closer to 90mph. And we have a locking convertor so there should be no slippage at cruising speeds on flat ground.
[/quote]
Thats for the 4 speed AT as requested, if you have the 5 AT then the ratios are different.
are these numbers using 2.0 ratios? I recently took a long trip in my 2.3 AT and 4000 rpm in 4th is much closer to 90mph. And we have a locking convertor so there should be no slippage at cruising speeds on flat ground.
[/quote]
Thats for the 4 speed AT as requested, if you have the 5 AT then the ratios are different.
[quote author=shabu link=topic=51301.msg826168#msg826168 date=1153028643]
mine is an 05 so I have a 4 speed. Can you post a link to your calculator? the only other reason I can think of for the numbers being so off is that me torque convertor really isn't locking up - but I'm pretty sure it is.
[/quote]
I use an excel spread sheet, you can google drivetrain calculator and come up with a few of them. Do a search for final drive ratio on this forum, the gear ratios were posted here quite some time ago. Hope that helps.
mine is an 05 so I have a 4 speed. Can you post a link to your calculator? the only other reason I can think of for the numbers being so off is that me torque convertor really isn't locking up - but I'm pretty sure it is.
[/quote]
I use an excel spread sheet, you can google drivetrain calculator and come up with a few of them. Do a search for final drive ratio on this forum, the gear ratios were posted here quite some time ago. Hope that helps.
For anyone still interested - according to this http://www.mazda3.co.nz/Specifications/default.aspx The final drive for the 4 speed 2.0 atx and the 4 speed 2.3 atx are different (I know thats from new zealand but I have seen the us specs and they are similar I just can't find them right now) 4000 rpms does calculate out to 92.5 mph using those numbers wich matches what I have actually seen in the car.
Ive read all ur answers...on the rev limit you can push the MZ3 5spd to about 7200rpm I tested it out one day because i didnt believe the 6500rpm limit..so if u wanna stretch it a little more do it but i suggest not to do it all the time once in a while. On the top speed my stops at 118-120..the gauge reads 140 anyway so i dont know wat the guy on the top said about going 155 unless hes got some crazy shit done to it.
[quote author=shabu link=topic=51301.msg828010#msg828010 date=1153152890]
For anyone still interested - according to this  http://www.mazda3.co.nz/Specifications/default.aspx  The final drive for the 4 speed 2.0 atx and the 4 speed 2.3 atx are different (I know thats from new zealand but I have seen the us specs and they are similar I just can't find them right now) 4000 rpms does calculate out to 92.5 mph using those numbers wich matches what I have actually seen in the car.
[/quote]
The charts posted here on the forums are correct for NA spec 3s. Also, the math is the math, it's only as good as the input. That being said, when I posted the numbers for the 4 speed ATX, that was assuming the same S model 2.3l that I did the 5MTX chart for. The i 2.0 model comes with 16" wheels and a different tire diameter so that could be throwing it off.
For anyone still interested - according to this  http://www.mazda3.co.nz/Specifications/default.aspx  The final drive for the 4 speed 2.0 atx and the 4 speed 2.3 atx are different (I know thats from new zealand but I have seen the us specs and they are similar I just can't find them right now) 4000 rpms does calculate out to 92.5 mph using those numbers wich matches what I have actually seen in the car.
[/quote]
The charts posted here on the forums are correct for NA spec 3s. Also, the math is the math, it's only as good as the input. That being said, when I posted the numbers for the 4 speed ATX, that was assuming the same S model 2.3l that I did the 5MTX chart for. The i 2.0 model comes with 16" wheels and a different tire diameter so that could be throwing it off.
I have the 05 2.3 S model - but from a little more searching http://www.mazda3forums.com/index.php?topic=47326.0 it looks like the final drive ratio on the 05 2.0i model may be different than the 03-04 so I wonder if it the same for the 05 "S". I know my math can't be too far off because I had the whole 13 hour drive from Central OR to San Diego CA to observe what speed I was going at what rpm.
currently all the 2.0 and 2.3 5 spd manual tranmissions in the US Mazda 3 share the same ratios - both gear ratios and final drive ratios are the same. The 5spd manual trans is identical on both the 2.0 and 2.3. In some other countries such as Japan they do have a different final drive for the 5spd manual it is 4.388 in the JDM models. The US models have a 4.105 final drive. Again this info only applies to 5 spd manual transmissions.
[quote author=hoffo link=topic=51301.msg833731#msg833731 date=1153353976]
currently all the 2.0 and 2.3 5 spd manual tranmissions in the US Mazda 3 share the same ratios - both gear ratios and final drive ratios are the same. The 5spd manual trans is identical on both the 2.0 and 2.3. In some other countries such as Japan they do have a different final drive for the 5spd manual it is 4.388 in the JDM models. The US models have a 4.105 final drive. Again this info only applies to 5 spd manual transmissions.
[/quote]
Thats good to know - and just to be clear - I have an automatic.
currently all the 2.0 and 2.3 5 spd manual tranmissions in the US Mazda 3 share the same ratios - both gear ratios and final drive ratios are the same. The 5spd manual trans is identical on both the 2.0 and 2.3. In some other countries such as Japan they do have a different final drive for the 5spd manual it is 4.388 in the JDM models. The US models have a 4.105 final drive. Again this info only applies to 5 spd manual transmissions.
[/quote]
Thats good to know - and just to be clear - I have an automatic.
[quote author=M3-S link=topic=51301.msg833983#msg833983 date=1153361579]
never really knew the details about gear ratios, anyone wanna do a quick explanation? And when driving hard i shift at 7000rpm, can it go higher i dunno and don't wanna find out but shifting at that rpm usually keeps me at 5000rpm in the next gear
[/quote]
There isn't nearly enough room here to explain, or time for that matter. To your final statement though, you want to shift where when you hit the next gear, your RPM will be at the top of the engines power curve. Mods that you have will change where that curve is and how wide it is. Your gear ratios will tell you what RPM you will be at for a given wheel speed. If the RPM spread is too broad, it may drop you into a lower RPM range where the engine doesn't make good power and thats why there is usually a big change from 1-2 1st is the "granny gear" and your vehicle fully loaded, towing a boat, stop sign at the top of a hill, needs that low gear to take off from a standing stop. The 2-3 is "close ratio" and some 3-4 is also "close ratio" for performance, you are usually accelerating in these gears, then 5 is real tall for highway cruising and fuel economy. In a racing application, you'll never be towing anything, and you'll never care about economy, so you might decide to use all close ratio gearing and final drive ratio setup to match track speeds. Thats why a 1/4 mile drag car in 1st gear will redline at 10MPH where a nascar in 1st is at idle doing 20MPH. (Not accurate but an analogy)
So to go back to the last statement, your 2000 RPM drop is not true for all gears because the reduction between each gear is not the same.
If you were looking for shift points then some analysis would be required for an accurate answer as to what is the best RPM to shift at.
This is not accurate, i'm doing this as an educational message and is again, not to scale. You would need to figure all this out all on your own for your particular application to be accurate.
First, you need to dyno the car and keep that handy.
Next figure RPM drop for each gear
1:2 1500
2:3 800
3:4 800
4:5 1000
Now on our ficticious car, peak is at 5000 RPM but is very flat from 4800RPM-6200RPM. Before 4800RPM there is a steep upward climb and gradual decline from 6200-7000 redline
So we don't want our engine to drop below 4800RPM So...
1:2 shift should be 4800+1500=6300RPM Remember we are above our peak curve here so if the numbers are higher at the beginning (in this case we shift at 6200RPM instead so we'll land in 2nd at 6200-1500=4700RPM with a bit of fudge factor because the gear change is not instant!
Ok, so now we shift at 6200 always? no. 2:3 gear changes (to keep close to that peak again) is
800RPM loss from 2:3
Peak power is 5000RPM
800RPM devide in half= 400 RPM (so we are in the center of the power through the whole gear) 5000-400=4600RPM is where we need to be at this gear change so in second gear, you're shifting (4600 + 800 = 5400RPM)
3:4 in the example is the same 5400 RPM shift point
4:5 well you're not going to get far because in the example 5 is an economy cruising gear, so all you're going to do is run it to redline in 4 then hit 5 just to keep off the limiter.
This is alot to grasp but the concept is all there. If you're really interested, take the info and run with it and see what it results in. If not, please ignore
never really knew the details about gear ratios, anyone wanna do a quick explanation? And when driving hard i shift at 7000rpm, can it go higher i dunno and don't wanna find out but shifting at that rpm usually keeps me at 5000rpm in the next gear
[/quote]
There isn't nearly enough room here to explain, or time for that matter. To your final statement though, you want to shift where when you hit the next gear, your RPM will be at the top of the engines power curve. Mods that you have will change where that curve is and how wide it is. Your gear ratios will tell you what RPM you will be at for a given wheel speed. If the RPM spread is too broad, it may drop you into a lower RPM range where the engine doesn't make good power and thats why there is usually a big change from 1-2 1st is the "granny gear" and your vehicle fully loaded, towing a boat, stop sign at the top of a hill, needs that low gear to take off from a standing stop. The 2-3 is "close ratio" and some 3-4 is also "close ratio" for performance, you are usually accelerating in these gears, then 5 is real tall for highway cruising and fuel economy. In a racing application, you'll never be towing anything, and you'll never care about economy, so you might decide to use all close ratio gearing and final drive ratio setup to match track speeds. Thats why a 1/4 mile drag car in 1st gear will redline at 10MPH where a nascar in 1st is at idle doing 20MPH. (Not accurate but an analogy)
So to go back to the last statement, your 2000 RPM drop is not true for all gears because the reduction between each gear is not the same.
If you were looking for shift points then some analysis would be required for an accurate answer as to what is the best RPM to shift at.
This is not accurate, i'm doing this as an educational message and is again, not to scale. You would need to figure all this out all on your own for your particular application to be accurate.
First, you need to dyno the car and keep that handy.
Next figure RPM drop for each gear
1:2 1500
2:3 800
3:4 800
4:5 1000
Now on our ficticious car, peak is at 5000 RPM but is very flat from 4800RPM-6200RPM. Before 4800RPM there is a steep upward climb and gradual decline from 6200-7000 redline
So we don't want our engine to drop below 4800RPM So...
1:2 shift should be 4800+1500=6300RPM Remember we are above our peak curve here so if the numbers are higher at the beginning (in this case we shift at 6200RPM instead so we'll land in 2nd at 6200-1500=4700RPM with a bit of fudge factor because the gear change is not instant!
Ok, so now we shift at 6200 always? no. 2:3 gear changes (to keep close to that peak again) is
800RPM loss from 2:3
Peak power is 5000RPM
800RPM devide in half= 400 RPM (so we are in the center of the power through the whole gear) 5000-400=4600RPM is where we need to be at this gear change so in second gear, you're shifting (4600 + 800 = 5400RPM)
3:4 in the example is the same 5400 RPM shift point
4:5 well you're not going to get far because in the example 5 is an economy cruising gear, so all you're going to do is run it to redline in 4 then hit 5 just to keep off the limiter.
This is alot to grasp but the concept is all there. If you're really interested, take the info and run with it and see what it results in. If not, please ignore
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