Fiat Punto Stability Issue on Highway?

[vtlreja2]

Hi guys, recently i did the highway trip in my punto mjd,
car rocked awesome, but there is one issue,
every time i pass by another vehicle there is a wave effect in car, and when i am exactly side by another vehicle, there is the pulling force towards that vehicle,
have to hold the steering tight and slightly turn to the anti force direction to overcome this situation.
punto is pretty heavy car, i m surprised by this behaviour of the car, is it normal ? and any remedies for that ?
this could be the risky affair, as if i dont pay attention the car could hit the vehicle whom i am overtaking.

the effect is more when i overtake above 100, as well as, the heavy vehicle.

another question also,
i was continously driving between 120 to 125, ocassionally touched 130, mileage shown 17.5 without ac and partial window open,
on the return i was driving between 90 to 100 with AC on Knob 1, mileage on MID shown 17.9,

would i get more mileage on AC at the higher speed rather than keeping the
window open ??

thanks in advance,

 

[stingray91]

re: Punto Stability Issue on Highway?

Ac needs certain energy from engine to cool, in city use we always not in same Rpm. Also we tend to be in low rom so low energy ,ac continuesly takes energy from engine,
But in highway its opposite, so you get more energy from engine and cabin cools faster and work left is to maintain the temperature so it only works in intervals, also windows down will increase drag
Read my thread
http://www.theautomotiveindia.com/f...ips-improve-your-car-s-fuel-efficiency-7.html

The behavior in highway is not normal thing may be due to aerodynamic nature of punto,
Check with other car in highway in side gets pull towards you. Ask your friend to drive his car near you ask him what he feels. If its only to you may be due to aerodynamic nature of car, because when we overtake the winds blasting from near car needs a space to Seattle when you get near it a pull towards inside happens due to pressure difference.
But check with sevice center for the issue.

 

[Crazy cat]

re: Punto Stability Issue on Highway?

No experience with Punto on open roads. But I have felt this in Swift, Verito vibe, Vento and even XUV. Wind should be heavy and when a vehicle crosses, mostly heavy vehicle, a gush of wind moves the car a bit. I felt this most in Swift.

 

[biker]

re: Punto Stability Issue on Highway?

High speed driving is recommended with Windows closed and AC ON.

 

[pravin1987]

Re: Punto Stability Issue on Highway?

coming to the pulling effect. i have experienced it in i10, swift, figo and dzire. i will share my experience. once i was driving i10 at a speed of 100, i was driving by the speed of a bus with driver window half rolled down. the vehicle pulled to the left side. i have to provide steering input to keep it straight.

the same experience with windows rolled up in a swift. i suspect the reason to be air. when driving at high speed, the cross winds pushes the car to side. this is more prominent when you are driving in the right lane where the divider has small plantations. the pull is more when you are by the side of a heavy vehicle, where air has no way to pass through.

on the other i have driven safari, city, above 100 on a high windy day, no such experience. from my point perspective suv's are weigh more, so they are not pushed away and sedans are low slung and air doesn't affect them.

regarding mileage with ac or without ac, shift first 2 gears at 2000 rpm and on open roads keep at the speed between 80-100 and mileage of 20 should be easy to achieve.

 

[multijet crdi]

Re: Punto Stability Issue on Highway?

Don't feel much drag on stock 15" in my Linea face it only when I overtake very big trucks normal hatches, SUV don't cause any problem.
Your Punto is equipped with 14" or 15" tires also have you checked air pressure and alignment.
Have you driven any other car on highway to know if the drag is excessive in Punto.

Did you reset trip meter before starting return journey 17.9km/l is low at 90-100 km/hr speed unless the traffic was really heavy and road was single.

 

[NH08]

Re: Punto Stability Issue on Highway?

In comparison to Punto, Brio is very light. However, I did not feel such a drag on highway while overtaking at speeds > 100 kmph in my Brio. It was reasonably stable on speeds in excess of 100 kmph. I have not driven Punto but always assumed that it would be more stable being heavier.

 

[vtlreja2]

Re: Punto Stability Issue on Highway?

hi guys here is another update of my punto, did 450 kms on highway,
first of all the title changed not done by me,
secondly, there is no stability issue in the car, only just there is the wave effect when i pass other heavy vehicle, otherwise the car is damn stable even on skinny 165mm tire,

In comparison to Punto, Brio is very light. However, I did not feel such a drag on highway while overtaking at speeds > 100 kmph in my Brio. It was reasonably stable on speeds in excess of 100 kmph. I have not driven Punto but always assumed that it would be more stable being heavier.

well i only feel some kind of wave effect in my punto, only above 100 kmph, below 100 nothing is there,

 

[vtlreja2]

Re: Punto Stability Issue on Highway?

Don't feel much drag on stock 15" in my Linea face it only when I overtake very big trucks normal hatches, SUV don't cause any problem.
Your Punto is equipped with 14" or 15" tires also have you checked air pressure and alignment.
Have you driven any other car on highway to know if the drag is excessive in Punto.

Did you reset trip meter before starting return journey 17.9km/l is low at 90-100 km/hr speed unless the traffic was really heavy and road was single.

well, i think you are right,
the tires are 14" and of 165mm,
also there is slight pulling towards left, chances of non proper wheel alignment be there, will properly align the tires first and notify the outcome

thanks

coming to the pulling effect. i have experienced it in i10, swift, figo and dzire. i will share my experience. once i was driving i10 at a speed of 100, i was driving by the speed of a bus with driver window half rolled down. the vehicle pulled to the left side. i have to provide steering input to keep it straight.

the same experience with windows rolled up in a swift. i suspect the reason to be air. when driving at high speed, the cross winds pushes the car to side. this is more prominent when you are driving in the right lane where the divider has small plantations. the pull is more when you are by the side of a heavy vehicle, where air has no way to pass through.

on the other i have driven safari, city, above 100 on a high windy day, no such experience. from my point perspective suv's are weigh more, so they are not pushed away and sedans are low slung and air doesn't affect them.

regarding mileage with ac or without ac, shift first 2 gears at 2000 rpm and on open roads keep at the speed between 80-100 and mileage of 20 should be easy to achieve.

thanks brother, i always shift every gear under 2k rpm hardly gone upto 2.2k rpm, only in 5 gear i hover around 3k rpm mark,
thanks

High speed driving is recommended with Windows closed and AC ON.

thanks brother.
yesterday did that only and i got the mileage around 18.3 on MID with AC on knob 1 and speed around 120.

No experience with Punto on open roads. But I have felt this in Swift, Verito vibe, Vento and even XUV. Wind should be heavy and when a vehicle crosses, mostly heavy vehicle, a gush of wind moves the car a bit. I felt this most in Swift.

Oh, surprised to hear that, even in Xuv,

Ac needs certain energy from engine to cool, in city use we always not in same Rpm. Also we tend to be in low rom so low energy ,ac continuesly takes energy from engine,
But in highway its opposite, so you get more energy from engine and cabin cools faster and work left is to maintain the temperature so it only works in intervals, also windows down will increase drag
Read my thread
http://www.theautomotiveindia.com/f...ips-improve-your-car-s-fuel-efficiency-7.html

The behavior in highway is not normal thing may be due to aerodynamic nature of punto,
Check with other car in highway in side gets pull towards you. Ask your friend to drive his car near you ask him what he feels. If its only to you may be due to aerodynamic nature of car, because when we overtake the winds blasting from near car needs a space to Seattle when you get near it a pull towards inside happens due to pressure difference.
But check with sevice center for the issue.

thanks mate, already gone through your thread,
only thing last to check it with proper wheel balancing and alignment,
will keep this thread updated,
thanks

 

[biker]

with AC Blower position in 1 or 2-3 or 4 does not affect your Fuel economy. the thing is, your car's AC Compressor is working. and the control in your dash is for "blower"(fan!). so, if you put it in 4th position car will not consume more fuel. it's a common assumption that the blower control is mistaken for Compressor cooling control. AC is not a refrigerator!

 

[generalmax]

+1 to biker.
The thermostat is the real controller.
AFAIK ,A cars mileage is inversely proportional to the speed after it crosses 80 Kmph. Normally for petrol vehicle you can find a sweet spot around 2K RPM in 5th gear which give you good mileage. The drag to a car is considerably higher above 75Kmph. Keeping the windows opened will create more drag. So it is recommended that you keep the windows closed with AC on at 80 Kmph or more.

The rolling/rocking effect you are talking is almost there for every car .The taller the car it will be more. I had seen it even when the vehicle is stand still irrespective of the model and make.

 

[vtlreja2]

+1 to biker.
The thermostat is the real controller.
AFAIK ,A cars mileage is inversely proportional to the speed after it crosses 80 Kmph. Normally for petrol vehicle you can find a sweet spot around 2K RPM in 5th gear which give you good mileage. The drag to a car is considerably higher above 75Kmph. Keeping the windows opened will create more drag. So it is recommended that you keep the windows closed with AC on at 80 Kmph or more.

The rolling/rocking effect you are talking is almost there for every car .The taller the car it will be more. I had seen it even when the vehicle is stand still irrespective of the model and make.

thanks @ biker and @ generalmax
will keep this thing in mind,

 

[hemantp]

I have never felt such issue in my Punto (2012 model) even at top speed but some points to consider:

1) Tyres - 15" 175 mm should give better ride
2) Drive with windows rolled up at high speeds
3) Check wheel alignment, air pressure
4) Is steering being honest? Do you still have that great feedback even at high speeds? Else something needs to be fixed.

 

[vtlreja2]

I have never felt such issue in my Punto (2012 model) even at top speed but some points to consider:

1) Tyres - 15" 175 mm should give better ride
2) Drive with windows rolled up at high speeds
3) Check wheel alignment, air pressure
4) Is steering being honest? Do you still have that great feedback even at high speeds? Else something needs to be fixed.

sorry for the late update, did the alignment and the issue is resolved now, only left pulling is still there otherwise there is no problem. i think wheel balancing is required and might be tyre rotation.

2. i drive with windows rolled up completely now,
3. done, all well
4. to be honest, steering is bit light above 110 but never felt disconnected, its still rock solid even at 140, feedback is also ok.

thanks.

 

[acechip]

Honestly I never felt this rocking issue in my
1) Santro
2) Nano (surprise)
3) Linea TJet (not expected to as well)
4) Micra CVT.

The only one where I felt the effect was actually my DZire. Maybe it also has something to do with the frame/suspension mounting, which in Dzire's case is sprung softly, and I had tall profile 14/80/165 tyres.