[sandeepmohan]

Originally Posted by TheTeacher

So guys, is something wrong with my car that I'm getting between 6 and 7 in Bangalore city traffic with a/c on all the time? Brakes catching, perhaps? Should it be looked at? The last time I was at Vecto to have mudguards installed, a mechanic went on a test drive with me for squealing brakes and said the squealing was normal if the disk and pads heated up. I mentioned the poor FE to him, and he didn't comment.

This is normal if you are a regular in a lot of stop and go traffic. Don't worry too much, it is not like the other petrol cars are that much better in consumption. My worst has been 7.7kmpl.

I changed my driving habits a little. I shift into the taller gears a little late. If the next gear takes the revs below 1700rpm, I don't up shift, I just stay in that gear even if it means getting on and off the gas and keeping the engine spinning at 2200rpm. The car seems to be a lot more efficient when driven this way. It appears to drink a lot of fuel when driven out of the turbo band and is most efficient when driven in the turbo zone.

As for brakes catching; on level ground, put the car in neutral, hand brake disengaged and push the car and check if it moves freely. Your wheel would have caught fire had the brakes been catching and you will surely get a burning smell from the brakes and more so from the clutch.

If squealing is consistent, you have a problem. I get it when the brakes are cold and if the car was just washed. It goes away after a couple of applications of the brakes or after they have warmed up. I don't have squealing brakes, its more a mild brake grinding noise that goes away.

[TheTeacher]

Originally Posted by sandeepmohan

I changed my driving habits a little. I shift into the taller gears a little late. If the next gear takes the revs below 1700rpm, I don't up shift, I just stay in that gear even if it means getting on and off the gas and keeping the engine spinning at 2200rpm. The car seems to be a lot more efficient when driven this way. It appears to drink a lot of fuel when driven out of the turbo band and is most efficient when driven in the turbo zone.

Sandeep, thanks a million for that.

It is my belief that any engine will forgive you a somewhat higher RPM (not talking about redlining here) but will curse you for lugging it. As a kid, I've seen drivers at home lugging and hated every second of it, but I was so young I couldn't so anything about. I have a real aversion to lugging, and with me it only happens when I suffer a brain fart, and I downshift immediately.

With the T-Jet, being surprised that I'm breaking records for the lowest FE, I've been shifting up much earlier than I'd like to. Initially I was doing it at ~ 2200 rpm, but have now cut back to ~ 1750. I don't like to shift up at anything less, unless I'm on a downslope. I'll follow what you've said and see if that makes a difference for me.

The mechanic at Vecto kept insisting that brake squeal was normal once the brakes were applied a few times (i.e., they've warmed up). Strangely enough, I don't have squeal when I'm starting out cold. However, when I first move the car, there is a lot of noise and some groaning; to me it appears that the brake pad return springs aren't doing their job when I release the handbrake, Movement of the wheel seems to kick the pads back to their normal position after the groaning and other noises. The mechanic said there were no adjustments for this as well.

[Santoshbhat]

Originally Posted by TheTeacher

Sandeep, thanks a million for that.

It is my belief that any engine will forgive you a somewhat higher RPM (not talking about redlining here) but will curse you for lugging it. As a kid, I've seen drivers at home lugging and hated every second of it, but I was so young I couldn't so anything about. I have a real aversion to lugging, and with me it only happens when I suffer a brain fart, and I downshift immediately.

With the T-Jet, being surprised that I'm breaking records for the lowest FE, I've been shifting up much earlier than I'd like to. Initially I was doing it at ~ 2200 rpm, but have now cut back to ~ 1750. I don't like to shift up at anything less, unless I'm on a downslope. I'll follow what you've said and see if that makes a difference for me.

The mechanic at Vecto kept insisting that brake squeal was normal once the brakes were applied a few times (i.e., they've warmed up). Strangely enough, I don't have squeal when I'm starting out cold. However, when I first move the car, there is a lot of noise and some groaning; to me it appears that the brake pad return springs aren't doing their job when I release the handbrake, Movement of the wheel seems to kick the pads back to their normal position after the groaning and other noises. The mechanic said there were no adjustments for this as well.

About the FE I'd say its too early to judge. Let the engine run in a bit and things should improve. Have you done any long highway runs? sandeepmohan has described it quite well. With turbo petrols you don't need to upshift quickly to get the best efficiency. The engine is more efficient when its aided by the turbo. So if you are out of the turbo zone you lose out on that. Stay in a such a gear that even if you lift off the throttle you are not losing momentum due to engine braking. Just coast if necessary then feed the throttle when you want to go faster.

Just a suggestion. Don't keep the MID to display the instantaneous fuel consumption or the avg consumption. Drive the car normally and enjoy the drive. You didn't buy a T-Jet to break the Limca book of records for best FE. Enjoy the drive! I am sure after some time you will understand the full characteristics of the engine, its powerband etc... and your choice of gears, clutch input and throttle input will be all the better for better FE.

Brake squeal so early is not a good sign. Check for stuck calipers. Jack up your car and try spinning each wheel with your hand. Ask somebody to hit the brakes and then release it. The wheels should spin freely. The front wheels normally show some resistance as they are the drive wheels. But if something's hindering them, they will be very hard to spin with your bare hands.

[sandeepmohan]

Originally Posted by TheTeacher

Initially I was doing it at ~ 2200 rpm, but have now cut back to ~ 1750. I'll follow what you've said and see if that makes a difference for me.

Let me try to make this a little more clear. What I meant to say is, shift gears well into the turbo band/zone. Shifting at 2100-2200rpm is perfectly alright (Except First gear cause the tall gearing does not let you go too far), provided the conditions allow it. Just make sure that when you move on to the next gear and start acceleration, the rpm is still in the region of the turbo which is why I said 1700rpm. Basically; don't let the rpm fall too low. If it drops below 1500rpm and you start accelerating, you are most likely out of the turbo zone and this is when the car tends to consume more fuel. You won't be lugging the engine, it just isn't the optimum engine rpm to be efficient.

As SantoshBhat has also mentioned, get rid of that annoying mileage indicator. It ruins everything. My colleague used to do this on his Punto 1.2 and complained of poor efficiency. He was a new driver too. One day, I took him for a slightly long and fast spin with optimum gear changes (Not exceeding 3000rpm), put the MID in default, came back to the parking spot and checked the MID and it indicated average efficiency of over 11kmpl. He was shocked that the car was more efficient after a spirited drive.

I completely forgot that your car is brand new. I took my car for a 500km highway run when the odo was reading less than 200km. I got about 11kmpl. I kept speeds under 110kmph by using the speed warning feature.

Originally Posted by TheTeacher

The mechanic at Vecto kept insisting that brake squeal was normal once the brakes were applied a few times (i.e., they've warmed up). Strangely enough, I don't have squeal when I'm starting out cold. However, when I first move the car, there is a lot of noise and some groaning; to me it appears that the brake pad return springs aren't doing their job when I release the handbrake, Movement of the wheel seems to kick the pads back to their normal position after the groaning and other noises. The mechanic said there were no adjustments for this as well

Here is what I experience. I don't use my car everyday. The guard washes the car in this gap period even if I do not use the car. My car is parked in neutral with the parking brake engaged. My parking area is level. When I do take the car out after a gap and assuming the car has been washed, there is a snapping sound (Like a tak noise) that comes off the rear brake pads. It is due to water entering the area when the guard washes the car or when the alloys are cleaned. I get the alloys cleaned at least once in seven days and this means a lot of water comes into contact with the disc/rotor unit, brake pad and caliper assembly. I live in a city that has hard water. The brake pad tends to jam against the disc/rotor but is released once the car is moved. It no longer jams after this. It won't jam if the car does not get washed too. I too experience a groaning noise inside the cabin. Can be heard very well if the windows are rolled up and you do not have any music or aircon running. This groaning noise goes away after the pads have scrubbed the rotor a fair bit. A km of gentle intermittent braking and there is no more groaning noise. Make observations on this if you don not wash your car or wheels.

[nareshov]

Originally Posted by khoj

...
Could you share the BMC filter part no and source etc, I would like to try it out. I have used a Cosworth CAI system in my Swift zxi and have installed a K&N typhoon kit in my Cedia last week. It has definitely improved the low gear response in the Mitsubishi. I would like to try out the BMC in the Jet to see what difference it makes to the vehicle's running.
...

Here you go: FB555/01
I purchased and got it fit from Red Rooster Performance.

[puchoo]

Thanks! This might explain the awesome economy of 16 which i got yesterday to the airport and back - while traffic was on the lighter side etc the gear changing was all happening within or a little short of the turbo range the entire trip unlike my office runs where i am shifting at 1500 RPM.

Originally Posted by sandeepmohan

Let me try to make this a little more clear. What I meant to say is, shift gears well into the turbo band/zone. Shifting at 2100-2200rpm is perfectly alright (Except First gear cause the tall gearing does not let you go too far), provided the conditions allow it. Just make sure that when you move on to the next gear and start acceleration, the rpm is still in the region of the turbo which is why I said 1700rpm. Basically; don't let the rpm fall too low. If it drops below 1500rpm and you start accelerating, you are most likely out of the turbo zone and this is when the car tends to consume more fuel. You won't be lugging the engine, it just isn't the optimum engine rpm to be efficient.

[TheTeacher]

Originally Posted by Santoshbhat

About the FE I'd say its too early to judge. Let the engine run in a bit and things should improve. Have you done any long highway runs? sandeepmohan has described it quite well. With turbo petrols you don't need to upshift quickly to get the best efficiency. The engine is more efficient when its aided by the turbo. So if you are out of the turbo zone you lose out on that. Stay in a such a gear that even if you lift off the throttle you are not losing momentum due to engine braking. Just coast if necessary then feed the throttle when you want to go faster.

Just a suggestion. Don't keep the MID to display the instantaneous fuel consumption or the avg consumption. Drive the car normally and enjoy the drive. You didn't buy a T-Jet to break the Limca book of records for best FE. Enjoy the drive! I am sure after some time you will understand the full characteristics of the engine, its powerband etc... and your choice of gears, clutch input and throttle input will be all the better for better FE.

Brake squeal so early is not a good sign. Check for stuck calipers. Jack up your car and try spinning each wheel with your hand. Ask somebody to hit the brakes and then release it. The wheels should spin freely. The front wheels normally show some resistance as they are the drive wheels. But if something's hindering them, they will be very hard to spin with your bare hands.

I agree, perhaps it's too early to worry. My benchmark is Puchoo, who's car is also new. If my FE was somewhere near his, I wouldn't worry, but it is currently very low - in MBZ / BMW territory or worse! Even our vintage Amassadors use to give at least 8 in the city! Unfortunartely haven't been able to go on a long run. I usually don't care about FE, but this is very low. The T-Jet is also the only vehicle I have, and hopping about doing errands really begs for an electric, but that's out of the question now. Maybe I will have to look into getting a small diesel runabout for that type of use. I do coast a lot, as soon as I know, I put her in neutral and let her coast.

Originally Posted by sandeepmohan

Let me try to make this a little more clear. What I meant to say is, shift gears well into the turbo band/zone. Shifting at 2100-2200rpm is perfectly alright (Except First gear cause the tall gearing does not let you go too far), provided the conditions allow it. Just make sure that when you move on to the next gear and start acceleration, the rpm is still in the region of the turbo which is why I said 1700rpm. Basically; don't let the rpm fall too low. If it drops below 1500rpm and you start accelerating, you are most likely out of the turbo zone and this is when the car tends to consume more fuel. You won't be lugging the engine, it just isn't the optimum engine rpm to be efficient.

As SantoshBhat has also mentioned, get rid of that annoying mileage indicator. It ruins everything. My colleague used to do this on his Punto 1.2 and complained of poor efficiency. He was a new driver too. One day, I took him for a slightly long and fast spin with optimum gear changes (Not exceeding 3000rpm), put the MID in default, came back to the parking spot and checked the MID and it indicated average efficiency of over 11kmpl. He was shocked that the car was more efficient after a spirited drive.

I completely forgot that your car is brand new. I took my car for a 500km highway run when the odo was reading less than 200km. I got about 11kmpl. I kept speeds under 110kmph by using the speed warning feature.

Sandeep, due to the nature of my driving, I was shifting up only at about 2000 - 2200 rpm (not because that was the turbo region, but because it felt right). However with the poor FE, decided to try shifting up at a lower RPM. It has helped somewhat, but I will go back to doing what I was doing before, which is what you're suggesting.

The groaning noise goes away for me too, once I've driven a few feet after a cold start in the morning. As Santosh mentioned, the return springs on the calipers need to be checked. But I find this disconcerting; none of my previous cars ever did that.

As for the squealing, I'll have to take it back to Vecto to have it looked at.

Thanks all for the help!

[Santoshbhat]

Originally Posted by TheTeacher

I do coast a lot, as soon as I know, I put her in neutral and let her coast.

Don't coast in neutral, but coast in gear. When you are coasting in gear, modern ECUs cut off fuel supply to the engine. When coasting in gear the engine consumes even lesser fuel than when the engine is idling . Also coasting in neutral is not very safe, as you will not be able accelerate quickly if the conditions demand it.

[saket77]

[quote=TheTeacher;3217139 I do coast a lot, as soon as I know, I put her in neutral and let her coast.[/QUOTE]

Originally Posted by Santoshbhat

Don't coast in neutral, but coast in gear. When you are coasting in gear, modern ECUs cut off fuel supply to the engine. When coasting in gear the engine consumes even lesser fuel than when the engine is idling . Also coasting in neutral is not very safe, as you will not be able accelerate quickly if the conditions demand it.

+1 to Santosh Bhat. Coasting in gear is the recommended thing, never in neutral though. Though, its completely upto the ECU programming of a particular car either to completely cut-off the fuel supply or to suppress it to a minimum, but coasting in gear certainly saves fuel when compared to coasting in neutral or with clutch depressed.

Also, keep an eye on the tyre air pressure, which can have drastic effect on the FE of you car.
If you want to read more about coasting, we have it on the forum here:

http://www.team-bhp.com/forum/techni...save-fuel.html

Regards,
Saket

[TheTeacher]

Yikes, this is news to me that coasting in neutral consumes more fuel. I always thought that in either case (in neutral or in gear) the fuel will be limited to idling amount. If there's a distance to go, coasting in neutral will get you there, but coasting in gear will slow one down from the engine braking effect and some more throttle may be required to get to the stop line.

[saket77]

Originally Posted by TheTeacher

Yikes, this is news to me that coasting in neutral consumes more fuel.

Once it was news to me as well

Originally Posted by TheTeacher

I always thought that in either case (in neutral or in gear) the fuel will be limited to idling amount.

Coasting in neutral will consume fuel identical to idling. Coasting in gear makes the ECU cut the fuel supply to minimum or even nil, depending on the ECU, since the wheels are driving the pistons via transmission.

Originally Posted by TheTeacher

If there's a distance to go, coasting in neutral will get you there, but coasting in gear will slow one down from the engine braking effect and some more throttle may be required to get to the stop line.

Yes, right, but that is another thing. But its not recommended to coast in neutral anyway, since you have zero engine braking (or acceleration) and hence compromised control inputs. Basically, its a wrong driving technique.

You will literally be amazed at the FE your car can deliver if you coast downhill in appropriate gears, which is the recommended way.

Regards,
Saket

[TheTeacher]

Boss, I NEVER coast downhill. Coasting is only on level ground, e.g., when a light turns red and there's some distance to go.

I disagree that there is complete loss of control; if one is ready to shift immediately there shouldn't be a problem. At least I've never had control issues because of coasting.

I'll try the coasting in gear thing with the T-Jet and see how that works out. Thanks.

[puchoo]

I do it coming down a flyover as well , i keep the speed in check and the foot on the brake ready to press but fairly safe. Ofcourse in Delhi , unless its at night one is still only moving at around 15-20kmph on the flyover as well.

Originally Posted by TheTeacher

Boss, I NEVER coast downhill. Coasting is only on level ground, e.g., when a light turns red and there's some distance to go.

.

[puchoo]

Did my office run today morning more along the lines of what SantoshBhat and Sandeepmohan suggested , also coasted more in gear rather than neutral. Got 10.5 by the time i parked and it climbed down to 10.3 KMPL by the time i had let the turbo cool down.

[sandeepmohan]

Originally Posted by puchoo

by the time i had let the turbo cool down.

There is no real need for engine idling for turbo spin down if the last km or more of the drive has been under 2000rpm. Chances are that the last bit of your drive leading to the parking is under 1500rpm. I let the fan run if it does kick in and this runs for about 20 seconds.

Last efficiency update on my car was 11.45kmpl tankful to tankful method. 70:30 City:Highway use.