Engine RPM
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Originally posted by silver fish:
oh reali? u the one hu say the physics serves no purpose. i wonder did u ever get into a secondary school before to study? think out of the box could u? oh ya how did u get here? did some leave your cage open?
people already giv in to you in a humble exit yet you call ppl a loser? me calling you a loser would be an insult to all the loser in the world. i hav came across decomposed cat on the expressway tat are so much less offensive than you.
stupid.
oh! whom am i calling "stupid"? i don noe. wat's your name?
u should do some soul-searching. mayb.. MAYB you will find one. don't lik my opinion of you? improve urself.
silver,
i believe u r not the first person to feel it this way,Nox are just too adamant about his opinion, he talk as if he cannot lose type of attitude,
i quited on him seriously.
MAybe u should too
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Originally posted by nightsky87:
Since he already mentioned that he has decided not to carry on with discussion of the topic, why must you still add in the 'loser?'
he like to call names.in fact he is the first to start this culture...
get used to it?
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Originally posted by tomsss:
theorectically yes. lower rpm = smaller combustion = lesser air and fuel mixture to create that combustion. You will of course consume less fuel then revving at a higher rpm.
lower rpm does not mean lower fuel consumption.you can have full acc ON Vs full acc Off at the same rpm...
Depends on your usage of elecricity.
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Originally posted by nightsky87:
No la no offense taken, no worries.. at the end of the day 'we're drivers too', live and let live i guess? lol
no doubts ,life is more than driving isnt it?
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Originally posted by mh2:
gabriel, noX always like that 1, no point talking to him,
he is jus not teachable la.
to put it simply he suck.
stop forming cheap alliance with pple u hardly know.. u suck urself and u know it... whoever got banned... whoever got pwned by allgertia and ae86tofu..... -
Originally posted by mh2:
silver,
i believe u r not the first person to feel it this way,Nox are just too adamant about his opinion, he talk as if he cannot lose type of attitude,
i quited on him seriously.
MAybe u should too
not that i cannot lose... juz that what u said simply sucked... and is most of the time fundamentally wrong.. -
Originally posted by mh2:
he like to call names.in fact he is the first to start this culture...
get used to it?
oh i was the one that started this clture??? whoever starts to call allgeritia girly and nox as nitrogen oxide.... mh2 u are the ultimate loser lah... -
Originally posted by mh2:
lower rpm does not mean lower fuel consumption.you can have full acc ON Vs full acc Off at the same rpm...
Depends on your usage of elecricity.
again u display ur complete lack of technical knowledge here by sprouting nonsense... fuel consumption is dictated by rpm... not whethere ur right foot is stepping on the pedal or not.... ur right foot might not be stepping but if u rpm is at 5000rpm it will consume 5000 rpm worth of petrol... and may i ask why does usage of electricity affect fuel consumption... seriously... u shld perhaps read up more.. rather than being so thick skin to go acknowledge brothers and pals anyhow juz bcos they supposedly is on ur side??? pple in the know will know u are a quack.. and will juz flame u.. and is it or is it not a coincidence that pple that "sided" with u have the same level of technical condemness as u??? ahhahh -
Maybe u can post yr technical knowhow in other Car forum and it will be useful to others, here is like dreamland for kids. I also dun think here is a good place to discuss technical detail. There r many ppl I met in car forum who r really good at car but not here.
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Originally posted by HolySniper:
bro u eg9 or eh8 ah? posted in edmw chius ish no reply.. lol.
how's ur mthly cost breakdown and conditions? care to pm me if not able to post here? cos i ish oso interested..
u pm mi in edmw rah~! i dun hav bills commitment, dats y i can afford
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Originally posted by ceecookie:
Nope.There IS a ECU for all cars.Its impt as it controls various aspect of the engine - much like the brain in our body.
Manual will also face fuel cut-off at redline.the only difference is of course,u cant play with tiptronic and the like in a manual car
u are wrong....not ALL cars have engine management....cars that run on carburettors dont have engine management
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Originally posted by tomsss:
ah tofu, come, share your car's efficiency's experience
my car? my car consumes more petrol when its out of the powerband (less than 2000RPM) so lower the RPM DOES NOT MEAN that u're consuming less fuel. when u are the vehs powerband (the range where u get the most torque) u are actually saving fuel cos of the engine not having to overcome inertia when accelerating or while operating...rememeber y do cars consume more petrol when during start/stop traffic as compared to highways? simple. cos the engine is constantly moving and not having to overcome inertia unlike when moving off so efficiency is at its fullest...
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Originally posted by n0x:
erm.. i dun think u know what u are talking about....
too low rpm WUN cause higher fuel consumption... too low rpm u buay tahan cause u to step harder WILL increase fuel consumption... so the inefficiency stems from ur right foot not from the engine.. wtf u talking about???
u listen to ur engine smooth?? what are u talking about...i din know smooth is a word to describe an engine at high revs... means what... ur engine is machiam from a mustang??? at low revs... gonna die car one but at high revs then can sustain the engine combustion??? those rented car of urs engine will feel smooth only at low rpm...above 2 plus reaching 3 the engine will start to sound like a person struggling to breath...
yah sure.. burn a hole in ur pocket and then earn some bragging rights about how u flushed ur money through the exhaust pipe of ur rented car which is not even meant to rev in the first place....
there is an optimal range for an engine... all the cars u listed above are 1.5 and 1.6 litres... their optimal range is around 2 if u are talking about fuel efficiency...
yes sure.. their max torque is around 3 plus... but u sure u need that much torque??? which is like a few more Nm than if u shift up at 2???
why are ur uncle and friend shifting up at 3 +... cos they stepping on the accelerator like no tmr.. like u loh... yes they are shifting up at peak torque... but their FC is going down the drain....
and from the way u speak... i can tell u are an immature driver.. what traffic light F1... pls get a life... u can shift up at the redline to boost ur oversized ego and listen to ur engine get breathless with asthma but ur car will still be slow...
hes not really wrong about that...see my prev post and u'll understand what i mean....cheers
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now bottom line is this.....your well u max out your Fuel efficiency depends on yr vehs powerband....(MH2 yea u are right abt this one) now:
Bigger displacement engines have more torque in the lower RPMS as opposed to smaller displacement engines so therefore when crusing @ top gear maintaining revs @ like 2-2.5K rpm is kinda okay...unlike my 1.3L car which has to maintain @ around 3-3500Rpms same goes for shifting.....for bigger displacement engines having a fatter torque curve @ the lower RPM range allows lower shifting points so please dosent mean that the lower u shift means that the lesser fuel u'll consume...cos if yea not in the powerband(too low a rpm) yr car will bog down and u'll have to depress more on the accelerator(more fuel) and the engine also has to overcome more inertia(again more fuel) so just go home and read the brochure abt the specs of your car...they dont print out the figures for nothing....and Nox,2-3K rpm no engine would sound like outta breath....its how the engine is designed(i will not go into details of cam duration,valve lift ,ignition timing and fuel pressure here) unless u're talking abt a china car...which runs outta breath at whichever RPMS
for a 1.6L car 2.5K-3 is the optimum...2K is too low man...when yea in the next gear it'll be like 1k plus RPM and the car will bog down....the only factor which wont make it happen is having a close ratio gearbox...something which is not favourable in street cars....so yea... -
woah tofu, tat was wat i wana say using the examples of bicycles. i stop replyin n0x not because i am a quiter or a loser, its is because it is pointless to argue with someone who never do much research and agrue against the facts. well, all he noe is to end the battle wif a loser comments..
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Originally posted by silver fish:
someone who never do much research and agrue against the facts. ....
strike la, the bull eyes.
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Originally posted by AE86tofu:
now bottom line is this.....your well u max out your Fuel efficiency depends on yr vehs powerband....(MH2 yea u are right abt this one) now:
for bigger displacement engines having a fatter torque curve @ the lower RPM range allows lower shifting points so please dosent mean that the lower u shift means that the lesser fuel u'll consume...cos if yea not in the powerband(too low a rpm) yr car will bog down and u'll have to depress more on the accelerator(more fuel) and the engine also has to overcome more inertia(again more fuel)
Ok, i admit i learn something new today
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Originally posted by silver fish:
woah tofu, tat was wat i wana say using the examples of bicycles. i stop replyin n0x not because i am a quiter or a loser, its is because it is pointless to argue with someone who never do much research and agrue against the facts. well, all he noe is to end the battle wif a loser comments..
juz by quoting someone else and saying what someone else said is what u wanted to say doesnt mean u know it... talk is cheap... the thing is ur knowelege is still suspect and ur phrasing is even more so... i can also quote tofu and say " wah tt is what i want to say" too... -
Originally posted by mh2:
strike la, the bull eyes.
again u only know how to take pot shots and piggy back on other pple... can u please stop being an irritating prick with no substance.. juz so u cant beat me in the technical aspects of things so u resort to these kind of lousy gurella tactics says a lot about ur character... -
Originally posted by AE86tofu:
now bottom line is this.....your well u max out your Fuel efficiency depends on yr vehs powerband....(MH2 yea u are right abt this one) now:
Bigger displacement engines have more torque in the lower RPMS as opposed to smaller displacement engines so therefore when crusing @ top gear maintaining revs @ like 2-2.5K rpm is kinda okay...unlike my 1.3L car which has to maintain @ around 3-3500Rpms same goes for shifting.....for bigger displacement engines having a fatter torque curve @ the lower RPM range allows lower shifting points so please dosent mean that the lower u shift means that the lesser fuel u'll consume...cos if yea not in the powerband(too low a rpm) yr car will bog down and u'll have to depress more on the accelerator(more fuel) and the engine also has to overcome more inertia(again more fuel) so just go home and read the brochure abt the specs of your car...they dont print out the figures for nothing....and Nox,2-3K rpm no engine would sound like outta breath....its how the engine is designed(i will not go into details of cam duration,valve lift ,ignition timing and fuel pressure here) unless u're talking abt a china car...which runs outta breath at whichever RPMS
for a 1.6L car 2.5K-3 is the optimum...2K is too low man...when yea in the next gear it'll be like 1k plus RPM and the car will bog down....the only factor which wont make it happen is having a close ratio gearbox...something which is not favourable in street cars....so yea...
tofu if u have might noticed... all along i am speaking with reference to cars in the 1.5litre and 1.6litre range... so my estimate of 1.5k rpm to 2.5k rpm is to me acceptableand i drive an altis... above 3k rpm in rev i feel that its breathless... maybe this kinda thing is subjective.... but i always felt tt the 3ZZ-FE is designed for cars to rev from sub 1rpm when idling to 3 rpm when accerlating... for maximum efficiency...
why do i say this? the max torque of the 3ZZ-FE is at 3800rpm.. according to what u are saying is true... then the powerband for my engine is ard 3000-4000... but the ECU prgramme it to shift up at less than 3krpm everytime.. unless i totally floor it... my car confirm dun have close shift ratios nor veh high final drive... it has only 4 gear ratios... having the abover 2 characteristics will cause it to be extremely inefficient when crusing at speeds of around 100km/hr...
which brings me to the point of fuel consumtption.. i still stick to the stand tt the lower rpm the less fuel consumed... it makes perfect sense... less combustion per minute less fuel consumed.....
though ur engine might be overcoming inertia with less torque...doesnt mean it is consuming more fuel.... it juz means tt less torque is used to overcome inertia.. hence u pick up speed slower... it will consume more fuel only when u step harder cos u cannot stand the slow accelration....
which also explains why in stop start situations u consume more fuel than in highway cruising.. i dun quite agree with ur explanation as above... what is the case is that when stopping and starting.. more often than not u are revving to 3krpm and more if u floor it... but if u are crusing ... most of the time u are doing 1.8krpm to 2.5krpm...hence this explanation coincides with what i have said in the above 2 paragraphs...
as for why ur car requires higher rpm.. its cos 1.3 litre produce less torque so u feel the need to utilized max torque everytime u accelerate... and also perhaps ur engine is an oversquare engine.. which has a shorter stroke and hence sacrificing the low end torque... as to why u need to maintain higher revs at crusing is also partly due to ur engine being an oversquare engine and partly due to power output...
which brings me to the next point... doesnt mean bigger engine have lower shifting point.. this is generally the case... but sometimes there are exceptions... like honda's b16a and b16b engines which have a max torque of 7k rpm and redlining at 8k rpm... sure u might attribute to it being vtec... but also partly due to the fact that the engines are oversquare engine... being bore larger than the stroke... (source: http://g-speed.com/pbh/b16a/index.html).. so engine design also plays a part...
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Originally posted by n0x:
tofu if u have might noticed... all along i am speaking with reference to cars in the 1.5litre and 1.6litre range... so my estimate of 1.5k rpm to 2.5k rpm is to me acceptableand i drive an altis... above 3k rpm in rev i feel that its breathless... maybe this kinda thing is subjective.... but i always felt tt the 3ZZ-FE is designed for cars to rev from sub 1rpm when idling to 3 rpm when accerlating... for maximum efficiency...
why do i say this? the max torque of the 3ZZ-FE is at 3800rpm.. according to what u are saying is true... then the powerband for my engine is ard 3000-4000... but the ECU prgramme it to shift up at less than 3krpm everytime.. unless i totally floor it... my car confirm dun have close shift ratios nor veh high final drive... it has only 4 gear ratios... having the abover 2 characteristics will cause it to be extremely inefficient when crusing at speeds of around 100km/hr...
which brings me to the point of fuel consumtption.. i still stick to the stand tt the lower rpm the less fuel consumed... it makes perfect sense... less combustion per minute less fuel consumed.....
though ur engine might be overcoming inertia with less torque...doesnt mean it is consuming more fuel.... it juz means tt less torque is used to overcome inertia.. hence u pick up speed slower... it will consume more fuel only when u step harder cos u cannot stand the slow accelration....
which also explains why in stop start situations u consume more fuel than in highway cruising.. i dun quite agree with ur explanation as above... what is the case is that when stopping and starting.. more often than not u are revving to 3krpm and more if u floor it... but if u are crusing ... most of the time u are doing 1.8krpm to 2.5krpm...hence this explanation coincides with what i have said in the above 2 paragraphs...
as for why ur car requires higher rpm.. its cos 1.3 litre produce less torque so u feel the need to utilized max torque everytime u accelerate... and also perhaps ur engine is an oversquare engine.. which has a shorter stroke and hence sacrificing the low end torque... as to why u need to maintain higher revs at crusing is also partly due to ur engine being an oversquare engine and partly due to power output...
which brings me to the next point... doesnt mean bigger engine have lower shifting point.. this is generally the case... but sometimes there are exceptions... like honda's b16a and b16b engines which have a max torque of 7k rpm and redlining at 8k rpm... sure u might attribute to it being vtec... but also partly due to the fact that the engines are oversquare engine... being bore larger than the stroke... (source: http://g-speed.com/pbh/b16a/index.html).. so engine design also plays a part...
when u say yr max torque is @3800 RPM u DONT have to shift @ 4k RPM!!!! what i meant is that u shift when yr engine is @ close to its max torque....like 3K rpm...besides yours is an auto right? gear ratios are already significantly lower than that of a manual as u only have 4 speeds instead of 5...i rest my case....
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I've been following this thread silently (a lurker u may call) and finally decided to give my vote of confidence to n0x.
This thread is an interesting read and both sides argued well.
However, n0x is "more correct" when he said that the less rpm u deploy, the lesser fuel consumed. This is a no brainer. Fuel consumption is directly linked to the rpm of the engine. This analogy is akeen to the more rice u consume, the more carbohydrates you will receive.
BUT, AE86tofu's argument went deeper and is more biased towards how to use a single drop of fuel wisely. He took into account of the sweet spot when u plot a graph of fuel consumed versus power output (typically non-linear), which perfectly makes sense in real life scenario...
Summary:
So what if n0x revs low, he's not getting the "sweet spot" power out of his engine even though it consumes less fuel per second in absolute terms. And hence he's not using a drop of fuel as wisely as you could have. (FUEL EFFICIENCY)
But hey, lesser rpm ===> lesser fuel burnt is only what he's trying to imply that's all! (FUEL CONSUMPTION)
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Actually, if anyone one of you have noticed... this thread started off with the TS asking how engine speed will affect the engine's longevity. Then somewhere in the middle of that first page alone, it started to slowly involve fuel consumption... then by the end of that page, we have 3 full pages of intense debate, most of which is not related to the topic.
ANYWAY... what pbeyondp sumed up is correct. Can't get any clearer than that.
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Originally posted by AE86tofu:
when u say yr max torque is @3800 RPM u DONT have to shift @ 4k RPM!!!! what i meant is that u shift when yr engine is @ close to its max torque....like 3K rpm...besides yours is an auto right? gear ratios are already significantly lower than that of a manual as u only have 4 speeds instead of 5...i rest my case....
thing is... i am not saying i have to shift at 4krpm... u said shift near 3800rpm... so if ur defination of near is +-800rpm... then erm meaning my powerband is 3000rpm to 4600rpm??? and my redline is 5600rpm...so hey suddenly i have an engine tt is akin to those continental cars with super flat torque curve throughout the entire rpm range...this cant be possible right...
i have seen the dyno run of my 3ZZ-FE... the torque curve is a parabola... it rises to the peak at 3800rpm and drops off the same way...
so what the ECU does is to maximise my fuel efficiency... i mentioned 3krpm... tt's when i am medium footed...
if i am light footed... i can get it to shift at ard 2500rpm to 2800rpm... and i have done it often.... so can tell the ECU is trying in whatever ways to juz keep it in the 2krpm range... which is hardly anywhere near 3800rpm... bcos the 2krpm range is enough to overcome inertia and get ur car picking up speed....
and my gear only has 4 speed... like i said it cant have close ratio and high final drive.. .neither can it have high gear ratios throughout like what u mentioned....imagine if my 4th gear is still above 1.000:1 ... then i will be crusing at 100 at 3 plus rpm... inefficient ....
if u need to know... the ratios are:1st - 3.643:1 2nd - 2.008:1 3rd - 1.296:1 4th - 0.892:1 and final drive 2.962... to me these are not veh high... i think its pretty evenly spread out though btw the 2nd and 3rd is quite far apart....
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So u driving Corolla.