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Old 5th December 2009, 15:24   #16
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See, a turbo car would give good FE below boost rpm because the fuel is well atomised along with air and leads to excellent combustion.
Once it starts boosting, there's gonna be a lot of air and to compensate for that, a lot of fuel also goes in.

The feature this engine is going to have to counter fuel consumption by a tad is the FSI (direct injection).
VVT-i is going to help with low end torque and help high rpm performance, but this is just theory since I don't know what the two different profiles are.
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Old 5th December 2009, 15:45   #17
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I m getting around 9kmpl from my tsi in the city, havent taken it on the highway yet..
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Old 5th December 2009, 19:02   #18
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[quote=nitrous;1617692]See, a turbo car would give good FE below boost rpm because the fuel is well atomised along with air and leads to excellent combustion.
Once it starts boosting, there's gonna be a lot of air and to compensate for that, a lot of fuel also goes in.

sorry, but what i say is the same engine ( TSI ) 1.8 ltr, has an idle RPM of @ 800, and the boost it gives is at 1850 RPM ( thats the purpose for TSI ), how could one drive in between such narrow power band for FE.
any way you drive the TSI it will deliver you @ 9-10 in
city, and upto 12 on highways......
but what i say we are not talking and discussing a product range say like Honda City or Fiesta, where FE is imp., rather you want to enjoy the TSI for which it is made, POWER UNLIMITED, and at very appropriate FE, why to think so much...go dude go...just buy it....
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Old 5th December 2009, 20:59   #19
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[quote=ganesh_evo75;1617920]
Quote:
Originally Posted by nitrous View Post
See, a turbo car would give good FE below boost rpm because the fuel is well atomised along with air and leads to excellent combustion.
Once it starts boosting, there's gonna be a lot of air and to compensate for that, a lot of fuel also goes in.

sorry, but what i say is the same engine ( TSI ) 1.8 ltr, has an idle RPM of @ 800, and the boost it gives is at 1850 RPM ( thats the purpose for TSI ), how could one drive in between such narrow power band for FE.
any way you drive the TSI it will deliver you @ 9-10 in
city, and upto 12 on highways......
but what i say we are not talking and discussing a product range say like Honda City or Fiesta, where FE is imp., rather you want to enjoy the TSI for which it is made, POWER UNLIMITED, and at very appropriate FE, why to think so much...go dude go...just buy it....
Most reviews of the 1.8 TSI engine fuel efficiency from UK and Australia, put it 8ltrs/100Km (12 kms/ltr) on the high way and 9.5 km/ltr.
I guess they use the recommended higher octane fuel.

My test drives of the Laura 1.8 TSI showed ~ 6Km/Ltr but this was in terrible peak hour crawling traffic (but with some very hard acceleration for brief periods ).

I am going to test my luck with this car !
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Old 5th December 2009, 22:04   #20
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Quote:
Originally Posted by SkyWalker View Post
ACI claims, its better than Altis & Civic although by a minor margin. City highway is 9.8/14 against 9.5/13.5 of Altis and 9.0/12.4 of Civic.
According to ACI data Altis is 10.5/15 and Civic is 9.2/13.2. Probably, sometimes they correct the data after some new findings.
Altis FE seems too good to be true.
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Old 5th December 2009, 23:01   #21
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Hey Imp,

I too was faced with a similar situation - a TSI or a TDI. TSI is a powerhouse. An efficient powerhouse, but a powerhouse nevertheless. 160 German horses man.

I see that you are from B'lore. Heard the traffic's pretty pathetic out there! Even with a 50-50 drive of city & highway, the turbo lag might let you down in the city. There goes your power & FE within a city. So, you might probably not get the best out. Moreover, a TSI is more like a refined RS like quattroa4 here has quoted here.

My suggestion - treat TSI as a mean machine giving better FE than others of the same category. Consider a TDI if FE is more important for you. TSI is probably best used on highways. City drive might actually let you down in the long run, especially in a city like B'lore.
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Old 5th December 2009, 23:31   #22
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Isn't it better to be in the low end of the turbo range than the high end of the non-turbo range? I mean if your turbo kicks in at 2400 rpm, won't the engine run more efficiently (Liter per Km, not Liter per Sec) at 2500 rpm than at 2300 rpm?
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Old 6th December 2009, 08:55   #23
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Quote:
Originally Posted by wildsdi5530 View Post
Isn't it better to be in the low end of the turbo range than the high end of the non-turbo range? I mean if your turbo kicks in at 2400 rpm, won't the engine run more efficiently (Liter per Km, not Liter per Sec) at 2500 rpm than at 2300 rpm?
Precisely what I was trying to say. But some people here believe otherwise.

Someone even said fuel is well atomised outside the turbo range.. I am not a mechanical or auto engineer, but logic tells me that turbo engine will be at it's most efficient when the turbo is working.
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Old 6th December 2009, 09:45   #24
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Quote:
Originally Posted by kuttapan View Post
Precisely what I was trying to say. But some people here believe otherwise.

Someone even said fuel is well atomised outside the turbo range.. I am not a mechanical or auto engineer, but logic tells me that turbo engine will be at it's most efficient when the turbo is working.

Thats what i mean to say.....i don't understand why do people makes it coplex when it is simple.
So please don't take negatively to Turbo's and supercharger's.
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Old 6th December 2009, 11:54   #25
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Quote:
Originally Posted by berj79
I m getting around 9kmpl from my tsi in the city, havent taken it on the highway yet..
Quote:
Originally Posted by ravich
My test drives of the Laura 1.8 TSI showed ~ 6Km/Ltr but this was in terrible peak hour crawling traffic
Now we talking!
A proper enthusiast's car.
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Old 6th December 2009, 12:14   #26
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Quote:
sorry, but what i say is the same engine ( TSI ) 1.8 ltr, has an idle RPM of @ 800, and the boost it gives is at 1850 RPM ( thats the purpose for TSI ), how could one drive in between such narrow power band for FE.
You haven't read my post clearly. I didn't say drive below boost rpm, i said drive at a "constant speed" below boost rpm. This you do only when you are cruising on the open highway (not in traffic).

When there is no change in vehicle speed or throttle pressure, being slightly below boost rpm will give you better FE since the amount of air and fuel being consumed by the engine is less. And when you feel the need to overtake, just increase the engine speed to above boost rpm and bring it down again when you want to maintain a constant speed.

The Variable Cylinder Mangement on the Accord V6 works something like this. When crusing at a constant speed, it switches off 3 cylinders making the engine breathe like a 1.75L 3pot engine (taking in less air which translates to less fuel being consumed) but as soon as you increase throttle pressure, it goes back to 3.5L V6 mode.

Shan2nu

Last edited by Shan2nu : 6th December 2009 at 12:21.
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Old 6th December 2009, 12:23   #27
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Quote:
Originally Posted by NannuBhai View Post
Hey Imp,

I too was faced with a similar situation - a TSI or a TDI. TSI is a powerhouse.

My suggestion - treat TSI as a mean machine giving better FE than others of the same category. Consider a TDI if FE is more important for you. TSI is probably best used on highways. City drive might actually let you down in the long run, especially in a city like B'lore.
Very wisely said Nannubhai.
by the way what IMP has to say finaly..??
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Old 6th December 2009, 13:43   #28
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IMP - I had the 1.8TSI on test for 5 days and all through the test she never averaged above 6kmpl in my hands. Mind you, I drive fairly hard and almost all of the driving was fast in-city driving.
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Old 6th December 2009, 14:01   #29
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[quote=Shan2nu;1618689]You haven't read my post clearly. I didn't say drive below boost rpm, i said drive at a "constant speed" below boost rpm. This you do only when you are cruising on the open highway (not in traffic).


Dear friend,
i still havent understood what are you talking about. you see i m useing a turbo charged RS for last 5 years , but whatever you are saying seems to be impossible to do it . reasons are
1> even at crusing speeds of say 80kmph (which is not at all a crusing speed) in 5th gear the rpm needle hovers around 2000-2200 rpm
2> if you mean crusing at 120 kmph , the needle shows 2600-2900 rpm depending upon the road conditions, wind speed , tyre pressure and state of your car n either ac is switched on/off
3> and even if you managed to go below 1850 rmp , i wonder the car will cruse or not , but it will definately limp or knock due to your higher gearing and slow speeds + quality of our fuels.
4> whats the point in taking a turbo charged vehicle and then driving it in non turbo mode at the first place ? better not to buy then
the laura tsi cant be driven at this rpm range whether you drive it in city or highway . and thats for sure.
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Old 6th December 2009, 21:35   #30
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Quote:
Originally Posted by Shan2nu View Post
You haven't read my post clearly. I didn't say drive below boost rpm, i said drive at a "constant speed" below boost rpm. This you do only when you are cruising on the open highway (not in traffic).

When there is no change in vehicle speed or throttle pressure, being slightly below boost rpm will give you better FE since the amount of air and fuel being consumed by the engine is less. And when you feel the need to overtake, just increase the engine speed to above boost rpm and bring it down again when you want to maintain a constant speed.

The Variable Cylinder Mangement on the Accord V6 works something like this. When crusing at a constant speed, it switches off 3 cylinders making the engine breathe like a 1.75L 3pot engine (taking in less air which translates to less fuel being consumed) but as soon as you increase throttle pressure, it goes back to 3.5L V6 mode.

Shan2nu
I am not an Auto Technical Expert. But the way I understand it, a car charged with Turbo is best used when the Turbo is in use. The car has been designed in the first place so that the Turbo is used. That's when the efficiency of the car is at it's best and is considered to be "optimally" used. By efficiency, I am not particularly talking about Fuel Efficiency. A car like TSI, like I said earlier, is a powerhouse. So, it's best used like one. You use the Turbo and that's when the car is running optimally.

If the car is used without the turbo in use, I am pretty sure, the logistics of the car will not match up very well. The whole point of a TSI is lost, if the turbo is not used at all.

We don't talk about Fuel Efficiency with cars like the Lambos or the Ferraris. TSI should be treated as such. Like I said earlier, the one thing that Skoda managed was to get better fuel efficiency, while still giving it vivacious power.
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