[variozin]

I purchased new fiesta 1.6 zxi petrol on 15th May. I just want to cross check my car's speed - gear - rpm match with a perfectly normal running
fiesta 1.6 petrol, or if it doesnt matter any car of similar spec.

In my car with Gear 4, and rpm 2000, the speed stays at abt 50~55km/hr.
If I remember well, it used to reach 60km/hr with rpm reaching 2000 for its first month of driving.

I am wondering why its there a drop in speed with respect to gear and rpm. Is it a normal behaviour for a new car when it is approaching its first service? or there is something wrong somewhere.

[arunforu1]

Look in owners manual, for correct RPM to change gears for economic driving.

Second question is quite confusing me: earlier 4th gear @2000RPM was = 60km/hr

now 4th gear @2000RPM = 50-55Kmph.......

See Tacho reading (RPM reading) is taken from engine's crankshaft, Gear ratio for 4th will remain same as it was, no matter how old a car is.

that means engine running at same speed, but less speed at wheel in same gear, this means:

1: Clutch slipping, which is highly unlikely with a new car.
2: Some thing wrong with Speedo. Generall speedos have error( but error is constant, dont change with time).
3: Faulty Tachometer (usually accompnied with electronic surges), most likely to happen with tachometer, even with small surges or leakage.

Remedy: Drive another fiesta petrol in 4th gear @2000 RPM it should be in same range.

Dont think something serious has happened wit hyou new car, Just drive & enjoy it.
Me too have a new fiesta diesel back at home & I must say, it is a refined vehicle.

[variozin]

thanks for your informative reply. I will try another fiesta 1.6. BTW its mostly advised not to drive with clutch half pressed while accelerating. But I think its not possible in backing and a little used in bringing the car into motion from stand still in 1st gear. So, I dont see any remarkable cause of clutch wear.
what do you say ? should I get my car raised on the hydraulic lifter for clutch examination?

[Shan2nu]

To calcualte the right speed you need to know the gear ratio, final drive ratio and wheel size.

I think the FD is 4.25:1, not sure about wheel size and 4th gear ratio though.

Shan2nu

[ariendj]

i got my fiesta 1.6 ZXi two days back..
i had a doubt about my tachometer reading!!i didnt want to start a new thread and so asking it hear..
when idling the car at traffic signals or bumper to bumper trafiic with ac on(blower at speed 2 and inside air recirculation on) i find the rpm at 1000 and not going down.
btw,the clutch is fully pressed

[abhinav.gupta88]

The clutch being full pressed does not change the car's rpm at idle.

Is it that the engine is cold at the time you are checking this reading?

[vnabhi]

Originally Posted by ariendj

i got my fiesta 1.6 ZXi two days back..
i had a doubt about my tachometer reading!!i didnt want to start a new thread and so asking it hear..
when idling the car at traffic signals or bumper to bumper trafiic with ac on(blower at speed 2 and inside air recirculation on) i find the rpm at 1000 and not going down.
btw,the clutch is fully pressed

That is the normal rpm at idling with AC on. It is generally 900 rpm without AC. So relax and enjoy the car.

[ariendj]

Originally Posted by vnabhi

That is the normal rpm at idling with AC on. It is generally 900 rpm without AC. So relax and enjoy the car.

thanks now its peace of mind for me!!

[ascertain]

No effect of stepping on clutch on the RPM mate!. Idle RPM values you mentioned are pretty ok.No worries.
You can always get a tacho check if not satisfied.