Unstable feeling at 110kmh, full load

[junchen]

Hi guys

have been enjoying my latio for the past 5 months. its really a spacious and fc friendly ride.

one thing to check with you guys here:
When my car is at full load (6 pax in car), the car will have a unstable feeling (a bit floaty on certain stretches of the highway) at 110km/h, even when going in a straight line. My previous ride, a 2006 CS3 Lancer doesnt have this prob though.

Last wk, i was going past a trailer truck at 90kmh (straight line again, but only myself in the car, no passengers) and as my car is side by side with the truck, i can feel the car being a bit unstable too, sort of like a floaty feeling. Sorry i'm not able to properly describe the feeling, but it does feel a bit scary.

My car is fully stock btw.

Does any bros here have the same experience?

Would a stiffer rear spring help? or strut bar? I wish to keep the car as stock as possible though.

[iwilly]

i try 150km/h alone or with 1 passenger still ok, quite stable. but the engine noise getting louder once u hit 140km/h

[SoL]

If you're on stock tires, there's the problem!

There's been a lot of past comments on how terrible the stock toyo tires are at high speeds. I'm curious btw, shouldn't more people in your car add to more weight and thus more stability?

[idiotboi89]

hmm maybe cause its my first car.. i think no problem leh ... 


either tat or i am too inexperienced to realize tat  =)

[nymin9]

agreed that tyres are impt. change to v2 195 will improve greatly. if budget allows upsize rims lor. 

[alangohek]

Hi guys

have been enjoying my latio for the past 5 months. its really a spacious and fc friendly ride.

one thing to check with you guys here:
When my car is at full load (6 pax in car), the car will have a unstable feeling (a bit floaty on certain stretches of the highway) at 110km/h, even when going in a straight line. My previous ride, a 2006 CS3 Lancer doesnt have this prob though.

Last wk, i was going past a trailer truck at 90kmh (straight line again, but only myself in the car, no passengers) and as my car is side by side with the truck, i can feel the car being a bit unstable too, sort of like a floaty feeling. Sorry i'm not able to properly describe the feeling, but it does feel a bit scary.

My car is fully stock btw.

Does any bros here have the same experience?

Would a stiffer rear spring help? or strut bar? I wish to keep the car as stock as possible though.

Hi Junchen,

Have tried travelling to around 130kmh with 5 passengers.

You mentioned taking 6 pax and that may cause the loading weight (Maximum Laden weight or gross vehicle wight - Kerb weight) of our car to be exceeded. The suspension system may not be capable of handling more weight than the loading weight. Try it with 5 pax, if symptoms persists, the problems could be due to the suspension system (shock absorber, damper or spring) or wheel alignment. You may want to consider bringing it to the workshop.

Rgds

[SoL]

Yes, like what alangohek, you might have exceeded the max weight. Also if you look at the tires, they show the pressure you must pump for maximum load. Mine is 300kPa.

That's not for comfort, that's for safety!

[alangohek]

Yes, like what alangohek, you might have exceeded the max weight. Also if you look at the tires, they show the pressure you must pump for maximum load. Mine is 300kPa.

That's not for comfort, that's for safety!

hey SoL

I checked with one of the SA of TCM that 300 kPa is on the high side and may decrease braking effectiveness on a wet day. Mine was 250K kPA and 230 kPa for front and back respectively.

[pizzaboy]

WaH 300kpa cannot lah too much pressure not advisable man dangerous, if u travel at high speed continuosly esp on nsh ur tyres might burst & give way...

Recommended is 32-33psi

[Gone with the wind]

Hi Junchen,

Our latio stock suspension is designed with comfort in mind, hence is very soft.  It is a normal seden, hence the aero dynamic is average.  When travelling at high speed, you start finding the car rocky, especially at cornering.  This is a common problem for cars with soft suspension.  Upgrading to harder suspension and install strut bar/anti roll bar certainly help.  Changing to a different brand of tires will not help much unless your tires are already in bad condition, only increase the width of tires thread and upsize the tires and rim will improve stability to your ride, but with higher FC.  I do agree some tires have harder side wall and will help improved cornering, but not much different if we are talking about using our stock rim size.

When you travel / over taking big vehicles like bus, trucks at high speed (or they over take your car at high speed), please be very very aware and careful!  The big vehicles will creat a big vaccum due to its size and speed, and 'pull' whatever objects (like you car) toward them!  As I mentioned earlier, the latio suspension is soft, aero dynamic is normal, and our car weight is consider light, so you will find our car very very unstable next to the them.  Advice:  do not drive too fast when you see big vehicles in front (anything above 100kmh have to be extra careful), and do not drive too near the big vehicle too, as the nearer, the bigger effect of vaccum.  Many cars got into accidents with big vehicles at high speed is partly due to the inexperience of drivers in such situation.  So be safe then sorry!

[SoL]

WaH 300kpa cannot lah too much pressure not advisable man dangerous, if u travel at high speed continuosly esp on nsh ur tyres might burst & give way...

Recommended is 32-33psi

Yes, that's the car manufacturer's recommendation. But on the tire, I saw this "max load 800kg on 40psi". That's why i said you need more air to support more weight(I think it make sense too).

Gonna find out more.

[pizzaboy]

Yes, that's the car manufacturer's recommendation. But on the tire, I saw this "max load 800kg on 40psi". That's why i said you need more air to support more weight(I think it make sense too).

Gonna find out more.

Yah correct more weight means more pressure, but dun forget dat u r drivin a saloon car not a goods van & how often in a week do u fetch a full load of 5 pax? If its a everyday affair then i tink u keep ur pressure at 37-38psi would be a safe guage

[clarence]

Yes, like what alangohek, you might have exceeded the max weight. Also if you look at the tires, they show the pressure you must pump for maximum load. Mine is 300kPa.

That's not for comfort, that's for safety!

If your tyres are pumped up to 300KPa, I suggest you reduce the pressure immediately, to 250KPa max, in the name of safety (even on a  full load).

[limck007]

If your tyres are pumped up to 300KPa, I suggest you reduce the pressure immediately, to 250KPa max, in the name of safety (even on a  full load).

i do agree too... max i pump is 265 infront , 255 at the back

[SoL]

If your tyres are pumped up to 300KPa, I suggest you reduce the pressure immediately, to 250KPa max, in the name of safety (even on a  full load).

Not to flame or anything, but why do you say reduce to 250kPa is safe?

[SoL]

http://www.cleanmpg.com/forums/showthread.php?t=11652

Read the above article first.

For my 6 months of inflating tires to 300kPa, I've experienced improve handling over my previous 250kPa tires. Turning is much more stable. Road noise increased, but that's manageable, considering Latio's road noise is quite loud by itself. Rolling resistance decreases, and I don't feel like I'm driving through mud like on 250kPa.

If you're talking about overinflating will lead to tires buldging at the center, that's an old-timer saying, since tires nowadays are steel-belted, and they ensure even wear. No, tires won't explode either( see the above article, 100kPa in each tire, plus the car is balanced on just 2 of them).

HOWEVER, DO NOT UNDERINFLATE. That is a far more serious case. Decreased handling ability, poor wet weather performance and decreased fuel economy all comes from poorly inflated tires. If a tire is underinflated, if flexes and twist more as it rolls, and absorbs more energy (thus doesn't roll as well). That energy is going into heating the tire, and increases wear.

If you're unsure you want to take the risk, or just find it dangerous for whatever reason, please don't do the uncomfortable. It's entirely up to you.

Always keep at 235kPa minimum. More if you like!~

[baobao]

I had travelled on NS highway at 175km/h.. cant go up liao..
was with my wife and some luggage, it do feel unstable above 140km/h..   

[pizzaboy]

I had travelled on NS highway at 175km/h.. cant go up liao..
was with my wife and some luggage, it do feel unstable above 140km/h..  

Ok lar previously i was on 16" rims runnin on Firenza ST03 i felt that even at 180km/h when i did a free-hand of the steerin, the car maintain straight and i felt it was quite a reliable car, at dat time i pump 230kPa to all four tyres.

[junchen]

Hi guys

thanks to everyone who replied. i havent been logging to the forum as i was busy at work.

Firenza ST03 - i used it in my previous ride with 17" rims. Not too good in the wet.

I guess as our ride is more tuned for comfort and thus i'll just drive slower and avoid large trucks travelling in high speeds.

Might get TC to take a look at the suspension system (shock absorber, damper or spring) or wheel alignment when i go there for my 10k servicing.

Am thinking of changing tyres but not so soon. How long does the tyre last before we need to change?

junchen

[RG]

Am thinking of changing tyres but not so soon. How long does the tyre last before we need to change?

junchen

If ur an average Driver should be able to last u 40,000km or 1yr ++?