Hi all. Is it true that the lower the rpm reading, the better of the car's fc?

Currently I'm driving a b14 sentra '97(A).
RPM = 2700 @ 110km/h
The FC is around 11-13km /l

I'm interested to know others car like toyota seg 1.6, myvi 1.3, toyota vios, city idsi, hyundai getz 1.4. Both auto and manual............
others model are welcome also, thanks.

summary :

Model RPM @ 110 km/h
nissan sentra b14 1.6(A) 2.7k
sentra b14 SR16VE engine 3.3k
nissan sunny 1.3(M) 2.6k
getz 1.3 2.6k
kelisa 1.0(M) 3k
kelisa 1.0(A) 3.7k
kancil 660(M) 4.2k
kancil 850EX(M) 4.2k
myvi 1.0(M) 3.6k
myvi 1.3(A) 3k
kenari 1.0(A) 3.6k
kenari 1.0(M) 3.4k
viva 1.0 (A) 3.7k
saga blm 1.3(A) 3.1k
saga blm 1.3(M) 3.6k
waja cps (M) 3.2k
waja mitsu(M) 2.9k
savvy amt 3.6k
gen2 campro >3k
persona 3.2k
wira 1.5(M) 3.2k
wira 1.5(A) 3.8k
wira 1.6(A) 2.6k
wira 1.6 mivec(A) 2.5k
wira 1.6(M) F5M221XPXL GB 3.1k
wira 1.3(M) 3.2k
iswara 1.3(M) 3.5k
iswara 1.5(A) >3.9k
satria gti 3k
satria neo 1.6(A) 3k
satria 1.6(M) 2.8k
perdana v6 2.8k
honda civic eg 1.6(A) 3.1k
honda city idsi 2.7k
honda city vtec 2.5k
Honda City 2009 i-VTEC (5AT) 2.5k @ 120km/h
honda accord 2.0(A) 2.3k
honda accord 2.4(A) 2k
honda accord CB3 3k
civic ej8 b16a(M) 4k
civic fd2 1.8 2.35k
honda crv(3rd gen) 2.1k
vios 1.5(A) 2.5k
camry 2.4(A) 2.1k
toyota seg 1.6(A) ae111 2.5k
avanza 1.3(A) 4k
wish 2.0(A) 2k
wish 1.8(A) 2.9k
lexus rx300 3.0(A) 2.7k
suzuki swift 2.7k
Isuzu Trooper 4JG2 3k
kia carens 1.8(A) 2.9k
naza suria 1.1(A) 3k
hyundai accent 1.5(A) 2.5k
fiat punto 1.2(CVT) 2.2k
mitsubishi galant 1.8(M) 3.1k
Mitsu Lancer 2.4l (4g69) 3.1k
mazda 929 2.0(A) 2k
mazda 323 1.6(M) 3.5k
chevy optra 1.6 2.5k
chevy aveo 2.5k
bmw e90 325i 2.5(A) 2.2k
freelander td4 2.0 diesel 2k
citroen c3 1.6 (semiAuto) 2.3k
ford lynx 1.8(A) 2.75k
golf gti 2.6k
saab 9-5aero 2.1k
saab 9-3aero 1.8k
my Audi A4 2.0(A) 2.2k
Benz C200 2.9k

This post has been edited by joanalooidog: Aug 27 2009, 09:39 AM

proton waja
2.8k-3k RPM @ 110km/h

This post has been edited by jlce10: Aug 1 2008, 09:17 AM

The lower the RPM, the more efficient the engine and hence better fuel consumption. However, it cannot be used as a comparison as the engine itself would be the main factor in the calculation of fuel consumption and not the gear ratio. Furthermore, there are no aftermarket parts to change gear ratios (too much work to be cost effective) and hence it is seldom a factor in the calculation of FC.

The gear ratio is only effective in calculation if you are comparing 2 cars of the same make, same engine but different gear ratios.

erm my persona rpm 3k at 110km/h, but my 1.3 getz around 2.6k @ 110km/h...

so my getz more effective?

but when hi speed, my persona more effective

persona high rev engine mah....................

my neo 1.3 RPM 3100 @ 110km/h

How could you have a range of 2.8k to 3k for your RPM? RPM per km/h is always fixed per gear and never changes until you suffer clutch slippage.

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Added on August 1, 2008, 9:23 amActually, it's more of low power and need a shorter gear ratio to keep the car moving at high gear.

This post has been edited by sleepwalker: Aug 1 2008, 09:23 AM

maybe his car is going downhill, so at 2.8 oledi got 110km/h

nono, i not sure its either 2.8k or 3k... should be 3k bah...

Which part of 'fixed RPM per km/h' that you don't quite understand? It's a constant and not a variable as the gear ratio is fixed per gear.

I think the valve timing mechanism will also affect the RPM reading. My Sentra 1.6 MT driving at 110km/h, the rpm will increase or decrease slightly a little bit, from 2800 to 3000 rpm.

different size rim will cause your speedo meter to over or under read and will make your rpm reading @ 110 km/h not accurate anymore

senario example
13" 110@3k
15" 120@3k <-- bigger rims cause the speedo meter to over read

dei, after change rims your speedo still the same reading. it's the actual speed that is different.
speedo reading is taken from gearbox, not gps/ satellite position tracking.

IT has nothing to do with the engine. Your RPM meter is screwed if it moves while you maintain constant speed, or that your clutch is slipping. Your RPM is calculated at the engine. It is transferred to the gearbox by a big flywheel and clutch and turns the gearbox. The gearbox has fixed gears that will change the RPM of the engine to the RPM of your wheel. Each gear has a fixed ratio.

I don't care even if you jack your car up and spin the wheels. If it is 3000rpm at 110km/h on the road, it is still 3000rpm at 110km/h when the car is jacked up in the air and the wheels spinning freely.

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Added on August 1, 2008, 9:44 amWrong. Rusty nail is correct. Your RPM per KM/H on your dashboard will still remain the same. The only thing that will change is your actual speed and not speedo speed, meaning if the police shoots the laser camera at you, then you will be driving at 120km/h but speed still show 110km/h. That is how bigger wheel OD will affect you. It will not affect your speedo but affects your actual speed.

This post has been edited by sleepwalker: Aug 1 2008, 09:44 AM

Bro, you are wrong.
He mean RPM vs KMH..
It really will change when u change bigger sport rim
Police laser camera will shoot on our KMH speed. but we also see the speed is correct.
Only the RMP change lower litter bit, but laser camera is capture our KMH meter, not RPM meter.

Use math calculation..You will get when u use
KM/H = RIM round per hour VS RP/M = Gear round per min

13" 110@3k (you will feel your car powerful, pickup damn good)
15" 120@3k (you will feel still power ok)
17" 125@3k (you will feel your car no power)


**PS: when down hill, my car can reach 110kmh with 1000 RPM.. cause use free gear.

This post has been edited by LeVis_Jeans: Aug 1 2008, 10:06 AM

Waja CPS (MT) 3.2k RPM@110km/h

Depending on which gear it's on.
I get around 2.5k (4th gear) at normal and 3k (3rd gear) if I really push....well it's an auto though...

My Gen2 campro engine also same.. consume petrol so much when RPM over 3k.

Wira 1.5(M) 3.8K RPM for 110km/h ..

You are wrong. It will not change. Your speedo comes from your gearbox. It is fixed. Changing the size of the wheel will not change the readings on your speedo meter. It does not matter whether you change to 20inch. If the rpm is 3000rpm at 110km/h on the respective tacho and speedo meter, it will remain at 3000rpm at 110km/h even if you change it to 20inch (even though you are travelling at 130km/h).

You have to remember that there are always 2 speeds.

1. KM/H on speedo meter (this cannot change as it is a fixed reading from the gearbox)
2. KM/H actual speed (this will change depending on the OD of your wheel)

What we are talking here is the reading on the speedo and tacho meter. Actual speed aka real speed aka speed captured by speed camera will change but not the reading on the speedo and tacho.

We are talking about the speed reading on the speedometer. That is the only speed that we know. You will NEVER know your actual speed until you get caught by the police or go through one of those speed indicators like the one on Kerinchi link.

This post has been edited by sleepwalker: Aug 1 2008, 10:04 AM