Seeking advice on optimal engine speed/gear selection.
#1
![KS](https://www.rx8club.com/images/icons/ks.jpg)
Hello! I just completed reading the new driver's sticky and I still had some questions to be addressed.
My ride is a 2004 Grand Touring, and it has held up very well so far... comparatively speaking. It is on engine 3 because engine 1 was identified as a factory recall and freely replaced, and the dealership ordered engine 2 for a different year's specifications (kept my car delayed for another month and free rental to comp), making my car dubiously blessed for having three engines under the same user with no flooding or blowouts being the cause for replacement. She is within tolerance as obtaining 16.5mpg during commutes and exceeding 24mpg on long stretches.
The question is: What are considered optimum gears for driving on roads per speed limit.
My car likes humming around 4k rpm, just short of one of the power bands where she will jump and become very responsive; not a good thing in traffic sometimes around 35mph and below.
I try to tune my driving between 3k-4.5k rpm because it is still responsive, I use a variety of gears from 2nd-6th on American roads and highways to spread wear, and I notice that I do not lag for much power when required.
I have read before that the engine is inefficient below 2-2.5k rpm, though it is still very smooth-just slow to react, and I have noticed that the engine does not like going below 800 rpm under most conditions.
I have accepted the maintenance needs of this vehicle (I went through a clutch at 65k miles) and it is a commitment financially as this is my daily driver. I've been forgiving with the dealership since I accepted the mark-up cost of them being the ones to install and replace factory parts.
The site is chock full of sharing stories about the rides, upgrades, and performance envelopes, what I am seeking is advice on how to daily drive this vehicle through most conditions. The advance stuff is for later.
I usually err on the side of safety and stay below 4.5k when I am cruising or amidst traffic.
Hills are interesting for me, I usually go to a lower gear or hover below that 4.5k threshold, and I am wondering if it is safe for me and my drivetrain to use engine-braking to maintain speed on downhill grades. I listen very closely to the transmission beside me and besides being a little louder since the clutch-replacement/half-transmission repair the drivetrain is still sounding "healthy" and responsive.
I know it is somewhat unsafe to downshift to a easy stop or reduce speed sometimes since there have been close calls where I intentionally use brakes just to indicate to other vehicles that yes, I am slowing down, and you need to pay attention because I am a manual driver who augments braking with sequential downshifting to reduce speed. Nothing is scarier than a vehicle exceeding the dimensions of the rear window fill the view of my rearview mirrors completely with an accompanying screech of their brakes. It is a good day when I can use gear shifting and gentle application of the parking brake to stop during commute and parking without ever using the brake pedal.
I will not go into details about components beyond the essentials, and really, I am looking for good advice about efficient driving (on the road, not maintenance!) that would put the least negative impact on this vehicle. I picked it up at 50,000 miles, and she is still holding strong at 75,000 miles, responsive, agile, and feisty. She's saved my life before on the road, from remaining in control through black ice during snap freezes, going from 55-0 in time from beginning an auto-pile up, through sucking underneath a doe on -you guessed it- an icy bridge (still contributed to killing the clutch and half the trans - preferable to skidding off Wyoming), and I would be interested in practical user advice on how to maintain her as a workhorse, not a weekend delight.
Thank you.
My ride is a 2004 Grand Touring, and it has held up very well so far... comparatively speaking. It is on engine 3 because engine 1 was identified as a factory recall and freely replaced, and the dealership ordered engine 2 for a different year's specifications (kept my car delayed for another month and free rental to comp), making my car dubiously blessed for having three engines under the same user with no flooding or blowouts being the cause for replacement. She is within tolerance as obtaining 16.5mpg during commutes and exceeding 24mpg on long stretches.
The question is: What are considered optimum gears for driving on roads per speed limit.
My car likes humming around 4k rpm, just short of one of the power bands where she will jump and become very responsive; not a good thing in traffic sometimes around 35mph and below.
I try to tune my driving between 3k-4.5k rpm because it is still responsive, I use a variety of gears from 2nd-6th on American roads and highways to spread wear, and I notice that I do not lag for much power when required.
I have read before that the engine is inefficient below 2-2.5k rpm, though it is still very smooth-just slow to react, and I have noticed that the engine does not like going below 800 rpm under most conditions.
I have accepted the maintenance needs of this vehicle (I went through a clutch at 65k miles) and it is a commitment financially as this is my daily driver. I've been forgiving with the dealership since I accepted the mark-up cost of them being the ones to install and replace factory parts.
The site is chock full of sharing stories about the rides, upgrades, and performance envelopes, what I am seeking is advice on how to daily drive this vehicle through most conditions. The advance stuff is for later.
I usually err on the side of safety and stay below 4.5k when I am cruising or amidst traffic.
Hills are interesting for me, I usually go to a lower gear or hover below that 4.5k threshold, and I am wondering if it is safe for me and my drivetrain to use engine-braking to maintain speed on downhill grades. I listen very closely to the transmission beside me and besides being a little louder since the clutch-replacement/half-transmission repair the drivetrain is still sounding "healthy" and responsive.
I know it is somewhat unsafe to downshift to a easy stop or reduce speed sometimes since there have been close calls where I intentionally use brakes just to indicate to other vehicles that yes, I am slowing down, and you need to pay attention because I am a manual driver who augments braking with sequential downshifting to reduce speed. Nothing is scarier than a vehicle exceeding the dimensions of the rear window fill the view of my rearview mirrors completely with an accompanying screech of their brakes. It is a good day when I can use gear shifting and gentle application of the parking brake to stop during commute and parking without ever using the brake pedal.
I will not go into details about components beyond the essentials, and really, I am looking for good advice about efficient driving (on the road, not maintenance!) that would put the least negative impact on this vehicle. I picked it up at 50,000 miles, and she is still holding strong at 75,000 miles, responsive, agile, and feisty. She's saved my life before on the road, from remaining in control through black ice during snap freezes, going from 55-0 in time from beginning an auto-pile up, through sucking underneath a doe on -you guessed it- an icy bridge (still contributed to killing the clutch and half the trans - preferable to skidding off Wyoming), and I would be interested in practical user advice on how to maintain her as a workhorse, not a weekend delight.
Thank you.
#2
With that type of post... you don't need advice.
You are doing fine.
Just make sure you redline once day.
When you spend allot of time in the city redline more often
You are doing fine.
Just make sure you redline once day.
When you spend allot of time in the city redline more often
#3
Thank you Razz. You have any fun stories or quirks about your ride? I am continuing to look for comparisons or observations from other drivers and what they've experienced and found to be very efficient, practical, or safe. Sometimes there's insights and scenarios I've never encountered that could help me out a lot. Like the flooding I've read about in these engines on the sticky, never went near it, hope never to induce it.
I graze the redline only as a I upshift when going into freeways or open stretches whenever I feel frisky and no one's around to get spooked; Semis can be your best friend as a little car if you know how to use them as barriers/road-surface sweepers. Actually hover in redline? Nah... too risky.
Even when I downshift, I make sure the highest it takes engine speed is 5k and below to avoid shocking the drivetrain. You get real good at reading grades and banks on severe turns just by letting the car go and focusing on turning. Counter-steer is just showing off with how tight this vehicle turns when applied correctly. Unless the angle is beyond 90*, there is no need for a sloppy S in exiting a turn that has a very tight radius of curve.
This vehicle has proven to be very fun/dangerous in snow/slush/ice. Part of the winter kit is cables for both front and rear wheels. The redundancy of the front is not for any type of driving traction anymore than having all four tires on gripping contact on the road, not simply on the points of propulsion.
During the silly days (read: foolish) when I thought it was fun to challenge every speeder on the road she's pushed 160mph using 5th/6th gear on I-70, but then I realized that was a quick way for me to get myself and innocent people killed, and treated it as the golden test -proven for curiosity's and never to be tried again.
I am a firm believer in grip-driving, and any time she beaks traction during optimal driving conditions, I tend to steer for wider lines in curves. Still well within tolerance of lean and cornering, but just tempting a trooper for a fatter paycheck with court-time.
I graze the redline only as a I upshift when going into freeways or open stretches whenever I feel frisky and no one's around to get spooked; Semis can be your best friend as a little car if you know how to use them as barriers/road-surface sweepers. Actually hover in redline? Nah... too risky.
Even when I downshift, I make sure the highest it takes engine speed is 5k and below to avoid shocking the drivetrain. You get real good at reading grades and banks on severe turns just by letting the car go and focusing on turning. Counter-steer is just showing off with how tight this vehicle turns when applied correctly. Unless the angle is beyond 90*, there is no need for a sloppy S in exiting a turn that has a very tight radius of curve.
This vehicle has proven to be very fun/dangerous in snow/slush/ice. Part of the winter kit is cables for both front and rear wheels. The redundancy of the front is not for any type of driving traction anymore than having all four tires on gripping contact on the road, not simply on the points of propulsion.
During the silly days (read: foolish) when I thought it was fun to challenge every speeder on the road she's pushed 160mph using 5th/6th gear on I-70, but then I realized that was a quick way for me to get myself and innocent people killed, and treated it as the golden test -proven for curiosity's and never to be tried again.
I am a firm believer in grip-driving, and any time she beaks traction during optimal driving conditions, I tend to steer for wider lines in curves. Still well within tolerance of lean and cornering, but just tempting a trooper for a fatter paycheck with court-time.
#4
Dudemanbro
iTrader: (2)
"I have read before that the engine is inefficient below 2-2.5k rpm, though it is still very smooth-just slow to react, and I have noticed that the engine does not like going below 800 rpm under most conditions."
where did you find that information at? the first sentence, that is. can anyone justify this?
where did you find that information at? the first sentence, that is. can anyone justify this?
#5
http://www.pistonheads.com/gassing/topic.asp?t=810653
(RX8 tangent in the middle)
http://www.autoweek.com/article/2011...IEWS/111229954
(in the comments)
http://answers.yahoo.com/question/in...4174505AAwFHcS
The remaining sources I found were either tangential or commented on lack of response at 2-2.5k rpm as I've noticed (fine for take-off, but once at speed...), the engine sounds like its trying do too much with not enough backing it up at those revs.
Granted its forums or answer bulletins, and not dedicated ones, but geared towards people like me who looked at the manual and wondered: well zoom-zoom is awesome and all, and its good to know what my idiot lights mean if/when they light up, but what does the factory recommend. Kinda crucial I believe, especially when its up to the driver when the vehicle is standard.
I feel a lag at those RPMs, and by that, I mean I have to apply more accelerator to get the same jump in speed until 6th for example comes to its own past 65mph, and to be truthful, 5th gear is truly the final acceleration gear if your aiming for a personal record; maybe its my deficiency as a driver, but I find the easiest response and control (to include handling grades, especially above 10-15%, which is when they get their own signs on mountain approaches) at 4k, anything more and I am definitely climbing in RPM and the accompanying noise (I shift and hold based on road speed, engine speed, and the sound of my engine and drivetrain -when I am louder than other vehicles in traffic, I tend to upshift).
I drove her the first 10k miles using low revs and I noticed myself relying on neutral and braking more often than I truly should. Just had my first brake discs changed less that 5k miles ago and I care not to repeat that experience till 120k mileage.
Please, I'm not trying to be snitty or defensive, just sharing what little 'research' I have found on the subject so far and my own experiences. What have you found that works for you?
Thank you.
(RX8 tangent in the middle)
http://www.autoweek.com/article/2011...IEWS/111229954
(in the comments)
http://answers.yahoo.com/question/in...4174505AAwFHcS
The remaining sources I found were either tangential or commented on lack of response at 2-2.5k rpm as I've noticed (fine for take-off, but once at speed...), the engine sounds like its trying do too much with not enough backing it up at those revs.
Granted its forums or answer bulletins, and not dedicated ones, but geared towards people like me who looked at the manual and wondered: well zoom-zoom is awesome and all, and its good to know what my idiot lights mean if/when they light up, but what does the factory recommend. Kinda crucial I believe, especially when its up to the driver when the vehicle is standard.
I feel a lag at those RPMs, and by that, I mean I have to apply more accelerator to get the same jump in speed until 6th for example comes to its own past 65mph, and to be truthful, 5th gear is truly the final acceleration gear if your aiming for a personal record; maybe its my deficiency as a driver, but I find the easiest response and control (to include handling grades, especially above 10-15%, which is when they get their own signs on mountain approaches) at 4k, anything more and I am definitely climbing in RPM and the accompanying noise (I shift and hold based on road speed, engine speed, and the sound of my engine and drivetrain -when I am louder than other vehicles in traffic, I tend to upshift).
I drove her the first 10k miles using low revs and I noticed myself relying on neutral and braking more often than I truly should. Just had my first brake discs changed less that 5k miles ago and I care not to repeat that experience till 120k mileage.
Please, I'm not trying to be snitty or defensive, just sharing what little 'research' I have found on the subject so far and my own experiences. What have you found that works for you?
Thank you.
#7
Made in England
iTrader: (5)
The only thing you should do differently is use you brakes to stop the car that is what they are designed for. A new set of brake pads all round is about $100. If you wear out you transmission you are looking at $$$$'s and a much hard job to replace.
Also the rotary will run better the harder you drive it but at the cost of fuel economy so pick your poison.
Also the rotary will run better the harder you drive it but at the cost of fuel economy so pick your poison.
#8
Registered
That's what's in the owner's manual, but I suspect a writer just cut-and-pasted it from somewhere else. Those shift speeds correspond to really low rpm, well out of the range where there's a comfortable amount of power.
Not the only thing in the owner's manual that's a cut-and-paste job.
Ken
Not the only thing in the owner's manual that's a cut-and-paste job.
Ken
#9
Flame On!
iTrader: (4)
I think it's for "better" mpgs. Or at least that was their intention. I've tried following it before but it's extreamly boring to drive like that.
I don't see the harm in engine braking, as long as you use common sense it shouldn't put any more wear on the tranny than normal acceleration would. I do it everyday, several times a day. Not to mention when you engine brake your saving a little bit of gas cause the fuel is cut off.
I don't see the harm in engine braking, as long as you use common sense it shouldn't put any more wear on the tranny than normal acceleration would. I do it everyday, several times a day. Not to mention when you engine brake your saving a little bit of gas cause the fuel is cut off.
![Smilie](https://www.rx8club.com/images/smilies/smile.gif)
#12
i never though that you would need to read a bout how to drive these car. but i try the low shift gear and it us the same amount of gas and harder to startit is also extreamly boring to drive like that. know i only drive in top gear and the car seam to run better i hit about 220km ever day this happen very fast and i still get 400 km per tank, no trouble starting and a very very happy guy
#13
Got Ink?
Shift points as rpms at any given speed is entirely dependent on enginge load and desired acceleration rate or to maintain a given velocity.
To maintain a moderate velocity on level ground, the engine load is relatively low so, a higher gear will do just fine to keep rpms in the low 3k range. A lower gear (rpms at or above 4.5k) for these same conditions will cause the engine coolant temps to rise unnecessarily which could lead to problems if done excessively.
When ascending a grade, the engine load increases. To maintain a given speed comfortably in this scenario, you should be in a gear that allows for at least modest acceleration. If you are in a gear that when you depress the gas pedal, there is little to no appreciable acceleration, downshift to a gear that will allow the car to do so.
When accelerating through the gears during daily driving up to the speed limit, I usually shift at 5-6k rpms. Once at the speed limit, I maintain the speed limit at 3.5-4k rpms. More aggressive acceleration sees higher rpm shift points, of course.
Generally speaking, speeds at or less than 35mph require lower sustained rpms as the air volume moving past the radiator is not sufficient to cool the engine at higher rpms at these speeds. When traveling at speeds of 35mph or less, I keep the rpms in the range of 2.5-3.5k rpms (assuming level ground or negative grades). At higher speeds (45mph and up) you can safely drive at higher rpms. 4-5k rpm is the range I typically drive at while cruising at highway speeds.
To maintain a moderate velocity on level ground, the engine load is relatively low so, a higher gear will do just fine to keep rpms in the low 3k range. A lower gear (rpms at or above 4.5k) for these same conditions will cause the engine coolant temps to rise unnecessarily which could lead to problems if done excessively.
When ascending a grade, the engine load increases. To maintain a given speed comfortably in this scenario, you should be in a gear that allows for at least modest acceleration. If you are in a gear that when you depress the gas pedal, there is little to no appreciable acceleration, downshift to a gear that will allow the car to do so.
When accelerating through the gears during daily driving up to the speed limit, I usually shift at 5-6k rpms. Once at the speed limit, I maintain the speed limit at 3.5-4k rpms. More aggressive acceleration sees higher rpm shift points, of course.
Generally speaking, speeds at or less than 35mph require lower sustained rpms as the air volume moving past the radiator is not sufficient to cool the engine at higher rpms at these speeds. When traveling at speeds of 35mph or less, I keep the rpms in the range of 2.5-3.5k rpms (assuming level ground or negative grades). At higher speeds (45mph and up) you can safely drive at higher rpms. 4-5k rpm is the range I typically drive at while cruising at highway speeds.
#14
The part about airflow at low speed is interesting and i might apply that style for sub 35 mph where the engine speed difference between 2 & 3 is over a thousand rpm.
My emergency range became 280 miles before i knew i was on fumes during cross-country driving. There were times wherevi could push it further, but no point like running out of gas to prove it.
Funny, the rotary mechanic at mazda said the same thing about pushing the car for better performance.
Thank you all for the feedback. At least one tip i might apply from this.
My emergency range became 280 miles before i knew i was on fumes during cross-country driving. There were times wherevi could push it further, but no point like running out of gas to prove it.
Funny, the rotary mechanic at mazda said the same thing about pushing the car for better performance.
Thank you all for the feedback. At least one tip i might apply from this.
#16
The shift points in the owner's manual are what the EPA uses when they test the fuel economy. They were almost certainly chosen to optimize efficiency for the EPA test cycle.
As for the "brakes are cheaper than an engine/transmission" argument against compression braking: If you are worried about engine braking, you should really avoid engine acceleration. Just try to avoid using the engine at all, because when you use the engine to apply torque, that really wears it out fast. Yes, that was sarcasm.
The advice typically given in owner's manuals for gear selection while cruising on level ground is to pick the highest gear in which the engine can smoothly accelerate when you press the gas pedal. If you press the accelerator and the engine shudders, you should be in a lower gear. The shift point chart in the manual is a decent approximation of what gear to be in when cruising.
More throttle uses more gas, and higher RPM uses more gas. Cruising at lower RPM is more efficient in general, even if you have to press the accelerator pedal further down. I don't think that the rotary engine is any different in that respect.
As for the "brakes are cheaper than an engine/transmission" argument against compression braking: If you are worried about engine braking, you should really avoid engine acceleration. Just try to avoid using the engine at all, because when you use the engine to apply torque, that really wears it out fast. Yes, that was sarcasm.
The advice typically given in owner's manuals for gear selection while cruising on level ground is to pick the highest gear in which the engine can smoothly accelerate when you press the gas pedal. If you press the accelerator and the engine shudders, you should be in a lower gear. The shift point chart in the manual is a decent approximation of what gear to be in when cruising.
More throttle uses more gas, and higher RPM uses more gas. Cruising at lower RPM is more efficient in general, even if you have to press the accelerator pedal further down. I don't think that the rotary engine is any different in that respect.
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