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Old 3rd November 2008, 13:34   #76
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Quote:
Originally Posted by rkavthekar View Post
That's Super!!!! I guess, you are effectively using your RPM meter and the new found way of shifting gears using RPM meter.
ya...my gear shifts are now purely RPM based. i dont even glance at the speedo. after much trial and error, i finally zeroed in on 2000RPM for upshifting and 1000RPM for down shifting. this encompasses almost the entire range of speeds possible in city conditions.

of course i dont shift at those RPM limits if i need short bursts of speed (>2000RPM) or when i need to deccelerate for a few seconds (<1000RPM) before picking up speed again. the excellent torque serves me well in these situations.

till now i have used 5th gear only on 2 or 3 occassions (no opportunity in town). most of my daily commute is on 3rd gear in speeds between 20 and 40kmph. i come down to 2nd (speeds 5 to 20kmph) where ever traffic condition demands it. on occassions when i can go faster over long stretches, i shift up to 4th at 40kmph and stick to around 50-60kmph.

this ensures that i hardly need to use the clutch unless i am shifting gears or find myself in stop and go traffic where I have to alternate between 1st gear and neutral.

i think these steps have played an important role in improving FE. not to forget tyre pressure. Vista's manual specifies ranges for front and back tyres, with FE getting prominence in higher ends of the range and ride comfort at the lower end. i have opted for a midrange pressure, leaning a little towards FE (but it hasnt affected ride comfort).
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Old 3rd November 2008, 13:51   #77
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Swift, wearing 195/60 R15 (30 PSI in the front, 28 in the back) rubber with alloys.
2400 Kms on ODO so far.
A/C on 99% of the time
Normal HP diesel, no additives, stock filter, always full tank to full tank refuelling
Most gear changes are @ 2000-2500 rpm, with the occasional burst of much-needed speed.

Pre- first service: 15.6 kpl, 15.6 kpl, 15.7kpl
Purely city-cycle running, sometimes in the most abysmal traffic conditions (long periods stuck in 1st, 2nd gear, lots of stationary idling)

Post first service: 16.2 kpl, 16.3 kpl
Same running conditions, but now with the occasional 'trousers-on-fire' run to get the exhilaration of the turbo surge.
Despite that, the FE's gone up slightly.

Last edited by ghostrider : 3rd November 2008 at 13:53.
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Old 3rd November 2008, 13:58   #78
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I believe a lot of it also depends on the quality of fuel. I fill it regularly from BPCL and measure tankful to tankful. Following are my figures.

Swift DDiS - March 07, 18500 kms
City - 14 - 16.5 km/l (AC on 70% of the time - slow moving traffic)
Highway - 19 - 23.5 km/l (AC on 80% of the time - 80 to 120 km/h)

23.5 km/l was achieved when I tanked up at BPCL company owned outlet. Otherwise it is between 19 to 21 km/l

Brijesh.
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Old 3rd November 2008, 14:45   #79
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Quote:
Originally Posted by CtrlAltDel View Post
the Vista was a revelation today! i filled her up today and got an astounding 19.43 kmpl!!!!

last week it was 16.x so its been a climb of nearly 3 kmpl! i hope this is maintained for a longer time.

Fuel: IOC normal diesel from the same petrol pump as always.

100% City conditions, 95% Aircon.
This is really amazing. Which IOC bunk was this that you regularly fill up? I fill up at Abids, near Big Bazaar outlet.

I too regularly fill up with IOC normal diesel only and when i switch i notice the difference on the lower side. IOC i get 14kmpl and any other bunk 13kmpl, driving style remaining the same within city limits.

Edit: I just realized this is my 2000th post

Last edited by mobike008 : 3rd November 2008 at 14:47.
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Old 3rd November 2008, 15:03   #80
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Quote:
Originally Posted by CtrlAltDel View Post
the Vista was a revelation today! i filled her up today and got an astounding 19.43 kmpl!!!!

last week it was 16.x so its been a climb of nearly 3 kmpl! i hope this is maintained for a longer time.

Fuel: IOC normal diesel from the same petrol pump as always.

100% City conditions, 95% Aircon.

Thats a good mileage for Hyderabad driving with AC. Do keep us posted when you drive on highways.
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Old 3rd November 2008, 15:56   #81
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2000 RPM upshift and 1000 RPM downshift?

Makes zero sense to me.

Upshifting at 2000 RPM means just as the turbo (fun) effect hits. Basically you're barely driving in the turbo band.
Downshifting at 1000RPM means one lugs the engine. Downshifting at that RPM means next gear will also mostly be out of turbo band.

Sarkar, turbo ne kya bigada hai. Standard accessory hai. Use kar lo
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Old 3rd November 2008, 16:00   #82
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Read the October '08 issue of Overdrive, has a comparision of all the three.
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Old 3rd November 2008, 17:21   #83
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Quote:
Originally Posted by mobike008 View Post
Which IOC bunk was this that you regularly fill up?
Shivam, near HPS. I have been filling in this pump since 1998 when I bought my first mobike and then my V2 and now this Vista.

Quote:
Originally Posted by phamilyman
2000 RPM upshift and 1000 RPM downshift?

Makes zero sense to me.

Upshifting at 2000 RPM means just as the turbo (fun) effect hits. Basically you're barely driving in the turbo band.
Downshifting at 1000RPM means one lugs the engine. Downshifting at that RPM means next gear will also mostly be out of turbo band.

Sarkar, turbo ne kya bigada hai. Standard accessory hai. Use kar lo
most of the time i am within the turbo band (1750 RPM +) with every up or down shift. there is no lugging or even a murmur of protest from the engine.

The speed limits listed in my post occur around 2000-2100 RPM.

lemme explain:

While upshifting:

in 2nd gear, 2000-2100 RPM produces a speed of 25kmph.
in 3rd gear, 2000-2100 RPM produces a speed of 45kmph.
in 4th gear 2000-2100 RPM produces a speed of 65kmph.

these are the speeds I upshft at and in the higher gear, it automatically starts from around 1750RPM, thereby maintaining the turbo. I dont upshift and then deccelerate.

while down shifting:

4th gear at 1000 RPM produces speed of around 38 kmph.
3rd gear at 1000 RPM produces speed of around 18 kmph
2nd gear at 1000 RPM produces speed of around 5 kmph

when i down shift at these speeds, the turbo is automatically maintained in the lower gear (since these speeds are in the upper bands of the lower gears). i dont down shift and then accelerate hard, unless its for some serious overtaking.

thats why i generally end up driving in turbo - 1750-2100 RPM. IMO, anything higher is neither required nor possible in average peak city conditions.

I do lose turbo when the car is slowing down towards 1000RPM but I cant help it - i cant keep revving in heavy traffic. even if i lose turbo accelerating again is smooth and easy in the same gear too (provided i dont lose much speed and require a downshift).

but I regain turbo as soon as i downshift. thats why downshifting at 1000-1200 RPM is no issue at all.

ergo: no lugging, no wheezing, no lost power requiring help from clutch. we can hardly feel the gear change and the car continues smoothly as before. climbing inclines is also a breeze.

i dont know if I made sense technically coz I dont know the principles of a turbo engine but I arrived at those conclusions after experimenting for a 2 days. this system serves me well and gives me what I want - less clutch use and more FE

I am planning a road trip to bangalore in december when I can push the turbo limits on the highway!
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Old 3rd November 2008, 18:34   #84
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19.43 kmpl!!!!
awesome mileage.you are lucky man
But i haven't seen a lot of Vista's in chennai.
Whether TATA pauses delivering Vista or people are not interested in buying.
Any how this car deserves what it should be.
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Old 5th November 2008, 08:33   #85
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ok cool. maybe its due to my swift experience which is slightly diff, so I shift at higher RPMs. My rule of thumbs are:
a. Turbo on the way up post 3rd gear,
b. Downshift directly to 3rd if speed falls to 40-50, else stay in turbo
c. No turbo in first two gears because they are used primarily in city crawls in traffic.

I get 19.x city driving, 18.x mall crawling (gurgaon short 5km drives), 21.x on the highways.

That said, idling speeds are pretty irritating - 10 kph is a tad too fast at crawling in traffic at times (read expressway tollgate queues daily) and I hate clutching.

@aks: Get used to it. MJDs deliver this mileage always!
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Old 5th November 2008, 11:18   #86
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21 KMPL - Highway - 50% AC

Palio MJD - 15000 km mileage
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Old 11th November 2008, 20:32   #87
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mileage on my Vista (when I filled it 2 days ago): 17.8 kmpl

it has come down from 19.43 I got last week but still very satisfying

Quote:
Originally Posted by phamilyman
I shift at higher RPMs. My rule of thumbs are:
a. Turbo on the way up post 3rd gear,
b. Downshift directly to 3rd if speed falls to 40-50, else stay in turbo
c. No turbo in first two gears because they are used primarily in city crawls in traffic.
a basic question here: what exactly is the relation between the turbo and the torque of a car? the thing is I dont know technicalities of turbo charged engine...

all i know is that a turbocharger uses the exhaust gases (at a certain engine RPM) to spin the turbine that generates extra power for the same quantity of fuel burnt (which leads to better FE, along with more horses).

i hope i am right so far

does the extra power provide extra torque?

in 3rd gear i usually drive above 1750 RPM that starts the turbo, but in slower traffic, i slow down to around 1000-1200 RPM in 3rd gear without "clutching". this also enables me to quickly accelerate when I find gaps in traffic or to cover small distances of relatively less traffic (before slowing down again).
if i have to go lower than 1000RPMs (<18-20 kmph in 3rd gear), i down shift to 2nd gear where I can cruise similarly even at 5kmph.
this is what i feel is giving me good FE. is there a way to handle the turbo better (leading to better FE)?

i rarely get to "rip" the car using the turbo power to the max (because of lack of opportunity in city) so you can call me rather sedate and defensive driver.
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Old 11th November 2008, 22:14   #88
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@ctrlaltdel- the turbo boost provides more oxygen for combustion, which also lets the ECU step up the amount of fuel supplied. so you do get more power and torque when the turbo is spinning at its optimum.

in the city- your driving style will give the best results as far as FE is concerned. just make sure there is no lugging.

on the highway- keeping revs at 2000-2400 rpm in 5th should give best results
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Old 12th November 2008, 10:11   #89
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@rippergeo, thank you! thank you! thank you!

That was indeed very enlightening.

I did'nt realize that fuel supply was also stepped up during Turbo boost i was under the impression that due to the compression extra oxygen was available making the combustion more energetic.

you have also given your idea of good driving style for best FE, again very enlightening for me!
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Old 12th November 2008, 19:21   #90
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@ aadiatplay- you're welcome, but I thought it was common knowledge. without an increase in the amount of fuel also supplied, the engine would run too lean with just the increased amount of air being forced in. thats bad news.
the efficiency of forced induction engines is also slightly better than NA engines usually. I'm not sure why, i've forgotten that bit I read.

I've been experimenting with new gear shift points, these days as my commute is now entirely through the city. will wait for the 600kms to be done before I can post the new mileage figures.
from standing starts, I use 1st then 3rd then 5th.
rolling starts 2nd to 4th.
traffic is dealt with by 3rd and 4th in idle with feet off all the pedals.
crawling is done by 1st and 2nd in idle.
tapping the accelerator usually provides enough torque for normal overtaking, even from idle in 3rd and 4th- The magic of "Pete's"
inspite of all this econo mode driving, my 14km commute in the morning takes 25 mins, and evening takes 45min. I just love this engine.
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