Mileage Mathematics.....

[Wheel]

As I was thinking buying a Vios would give me a whopping 18kmpl fuel efficiency, and will make me more savings over my N16, just worked out the numbers as follows. Pls consider following robust numbers take ONLY fuel consumption into account. No depreciation or inflation is considered.

How mileage affects…

Vios Price = 2400000

N16 Price = 1800000

(a) If I buy Vios over N16, the extra expenditure = 600000

Vios fuel efficiency (at it’s best) = 18kmpl

N16 Fuel efficiency (at it’s best) = 13kmpl

I assume I run 1000km per month. Then monthly fuel consumption for,

Vios = 1000/18 = 55.6 ltrs

N16 = 1000/13 = 76.9 ltrs

Saving I have if I buy Vios = 76.9 – 55.6 = 21.3 ltrs * 115 = Rs. 2449.50 Per month

If I am to recover my extra expenditure at (a) by this monthly saving, number of months I have to run my Vios = 600000/2449.5 = 244.9 months = 20.4 years.

So, spending more 6lkhs for a Vios over N16 is profitable for me after 20 years!

I cant believe this is correct. Pls correct me if i've mistaken somewhere...

Your comments are welcome!!

[harshansenadhir]

As I was thinking buying a Vios would give me a whopping 18kmpl fuel efficiency, and will make me more savings over my N16, just worked out the numbers as follows. Pls consider following robust numbers take ONLY fuel consumption into account. No depreciation or inflation is considered.

How mileage affects…

Vios Price = 2400000

N16 Price = 1800000

(a) If I buy Vios over N16, the extra expenditure = 600000

Vios fuel efficiency (at it’s best) = 18kmpl

N16 Fuel efficiency (at it’s best) = 13kmpl

I assume I run 1000km per month. Then monthly fuel consumption for,

Vios = 1000/18 = 55.6 ltrs

N16 = 1000/13 = 76.9 ltrs

Saving I have if I buy Vios = 76.9 – 55.6 = 21.3 ltrs * 115 = Rs. 2449.50 Per month

If I am to recover my extra expenditure at (a) by this monthly saving, number of months I have to run my Vios = 600000/2449.5 = 244.9 months = 20.4 years.

So, spending more 6lkhs for a Vios over N16 is profitable for me after 20 years!

I cant believe this is correct. Pls correct me if i've mistaken somewhere...

Your comments are welcome!!

good point you're trying to make. However if you happened to run 2000km a month then the time taken to recover additional capital amount would be 10 years. Further if we assume the fuel prices are to go up in an exponential curve due to limitations in supply, this time duration would further reduce. Further, if Vios is newer than the N16, some maintenance costs too would have to consider and on the other side you have to consider the higher insurance premium for the expensive car, say Vios in this example.

This comparison can be done to vehicles of same class, but if you're paying more due to an upgrade, the value you pay on added comfort, luxury cannot be compared outright.

[heavyD]

Not to sound rude but, you know what I think? If everyone who owned a vehicle was as considerate and sensible with their driving manners as much as they cared about fuel economy, it would make the daily drive a lot more enjoyable and easier. Not to mention save a buttload of fuel in the process.

[YALA]

good hypothesis..but getting 18kmpl and 13 is alone optimistic...idealy if you have the two vehicles of each kind you can check how well it does on fuel and then do the computation. i do roughly 3000 clicks every month so in terms of millage you should use how much you drive on average. that would prob be the best estimation based on the individual needs.

[Sifaan]

As I was thinking buying a Vios would give me a whopping 18kmpl fuel efficiency, and will make me more savings over my N16, just worked out the numbers as follows. Pls consider following robust numbers take ONLY fuel consumption into account. No depreciation or inflation is considered.

How mileage affects…

Vios Price = 2400000

N16 Price = 1800000

(a) If I buy Vios over N16, the extra expenditure = 600000

Vios fuel efficiency (at it’s best) = 18kmpl

N16 Fuel efficiency (at it’s best) = 13kmpl

I assume I run 1000km per month. Then monthly fuel consumption for,

Vios = 1000/18 = 55.6 ltrs

N16 = 1000/13 = 76.9 ltrs

Saving I have if I buy Vios = 76.9 – 55.6 = 21.3 ltrs * 115 = Rs. 2449.50 Per month

If I am to recover my extra expenditure at (a) by this monthly saving, number of months I have to run my Vios = 600000/2449.5 = 244.9 months = 20.4 years.

So, spending more 6lkhs for a Vios over N16 is profitable for me after 20 years!

I cant believe this is correct. Pls correct me if i've mistaken somewhere...

Your comments are welcome!!

Adding to Harshan's points...

if you would likely use the car in the city, then the fuel efficiency figures would be much less, and the difference also likely less (maybe 12 vs. 9)? In that case the "recovery" period would be longer.

Plus you also need to consider finance cost (the extra 600,000 either means a bigger loan and more interest; or if you had the cash anyway, still there is opportunity cost as you can't put it in the bank/stock market/your business/other improvements in your lifestyle)

But the biggest numeric factor you must consider is the resale value of the vehicle. e.g. let's say you would sell the car in 2 years and both cars would depreciate by 10%. Then the Vios loses 240k and the N16 loses 180k. So in 2 years time would you have saved 60k with fuel/insurance/maintenance/finance charges/etc?

unless you are going to put the car in a cab service (in which case the mileage numbers get magnified a lot and just about nothing else matters) it's only worth to do this kind of analysis across different models if you can also put a value on things like:

- prestige value of the vehicle (looks, rarity, etc)

- comfort factor

- safety

- driving pleasure / performance

- space (legroom for driver, passengers, cargo)

- availability of parts

on the other hand, in this crazy market, it's possible for both models to depreciate at different rates, to even appreciate in price, or one to appreciate and other depreciate, so that pretty much makes all calculations go bonkers

[jehan80]

good hypothesis..but getting 18kmpl and 13 is alone optimistic...idealy if you have the two vehicles of each kind you can check how well it does on fuel and then do the computation. i do roughly 3000 clicks every month so in terms of millage you should use how much you drive on average. that would prob be the best estimation based on the individual needs.

I think the point he's trying to make is that even if hypothetically a car does as much as 5km more per litre, the duration it would take for it to actually translate into savings. Strictly taking only fuel consumption that is...

[Wheel]

Yes, Jehan you r correct. Like Big_D pointed out my intention is to show how crazy the people who r running behind cars with 2-3kmpl better fuel eff, and the same criticizing bit lower mileage ones. As I have heard, FB15 got the major attention of the market due to 1-3kmpl efficiency than N16 which is the younger product continued production even when FB series discontinued.

Like Harshana and Sifaan said, other factors should also taken into account. But what i needed to see is the actual importance of these kmpl figures people r chasing behind like it'll save the whole living... Finally what i got out from these figures is that if one should buy a car, fuel economy may be somewhere lowest in his checklist compared to the price tag (ofcrz it shouldn't be worse, something average will do it). Other factors you all have pointed out should come first in the list. But I've heard that Vios is one of the worst suspensions in Toyota. (Is it still better than N16?, if it is so, no wonder, that's Toyota)

BTW, like Yala mentioned, it is my average running (1000km per month) and the 13kmpl is what my N16 gives me out when im on bit long-less traffic drives. (of crz that's wt i use my car for) Vios thing is extracted from AL classifieds.

[harshansenadhir]

Yes, Jehan you r correct. Like Big_D pointed out my intention is to show how crazy the people who r running behind cars with 2-3kmpl better fuel eff, and the same criticizing bit lower mileage ones. As I have heard, FB15 got the major attention of the market due to 1-3kmpl efficiency than N16 which is the younger product continued production even when FB series discontinued.

Like Harshana and Sifaan said, other factors should also taken into account. But what i needed to see is the actual importance of these kmpl figures people r chasing behind like it'll save the whole living... Finally what i got out from these figures is that if one should buy a car, fuel economy may be somewhere lowest in his checklist compared to the price tag (ofcrz it shouldn't be worse, something average will do it). Other factors you all have pointed out should come first in the list. But I've heard that Vios is one of the worst suspensions in Toyota. (Is it still better than N16?, if it is so, no wonder, that's Toyota)

BTW, like Yala mentioned, it is my average running (1000km per month) and the 13kmpl is what my N16 gives me out when im on bit long-less traffic drives. (of crz that's wt i use my car for) Vios thing is extracted from AL classifieds.

Good point mate, but it isn't new to this forum. In fact all of us members have a good laugh about people who keep on worrying about few km's a vehicle can fetch for a litre. Not that we recommend to run fuel guzzlers all the time for day to day city running but being cynical and sarcastic about fuel consumption is only being the evaluation criteria.

[heavyD]

I'd be lying if I said I don't think about fuel economy (believe me, 6 kmpl ain't easy to live with ) but there's a limit! Worrying constantly about it is like buying a house and sitting in the dark at night to save up on the light bill... it kills the whole experience. Why not just enjoy your car? It's the easiest thing to do imo, as opposed to constantly worrying. If you can't and still wanna save money, well then, there's always public transport...

[Sifaan]

I'd be lying if I said I don't think about fuel economy (believe me, 6 kmpl ain't easy to live with ) but there's a limit! Worrying constantly about it is like buying a house and sitting in the dark at night to save up on the light bill... it kills the whole experience. Why not just enjoy your car? It's the easiest thing to do imo, as opposed to constantly worrying.

While agreeing with what you have said, I think there's also situations where you really should be aware of your fuel efficiency - i.e. if you are getting much lower efficiencies than the norm for that model, (after correcting for city/outstation driving) then it's an indication to check if anything needs replacement/cleaning. Some things like underinflated tyres you can check regardless (assuming the driver knows what pressure he should be using!) but it can be a good reminder for things like injector cleaning / fuel system cleaning (anything that doesn't happen every service).

Or it could just be an indication that you need to change your driving habits!

btw why is this in the Mitsubishi forum?

[heavyD]

While agreeing with what you have said, I think there's also situations where you really should be aware of your fuel efficiency - i.e. if you are getting much lower efficiencies than the norm for that model, (after correcting for city/outstation driving) then it's an indication to check if anything needs replacement/cleaning. Some things like underinflated tyres you can check regardless (assuming the driver knows what pressure he should be using!) but it can be a good reminder for things like injector cleaning / fuel system cleaning (anything that doesn't happen every service).

Or it could just be an indication that you need to change your driving habits!

btw why is this in the Mitsubishi forum?

True, it's best to always keep your vehicle in shape, in order to get the best out of it, and subsequently help in the long run too. And as far as driving habits go, I guess you've got to get used to your car and figure out how it performs best. For example, I hear everyone say you gotta shift at the lowest rpm possible, but my car seems to do better on fuel when I shift at higher rpms! So, I guess it's all about having fun finding out for yourself. These days I try to shift at around 4 -5K all the time, just to see what I would get...

And people should just drive faster! I guess a lot of people think that simply driving slow is the best way to conserve fuel.

[Sifaan]

And as far as driving habits go, I guess you've got to get used to your car and figure out how it performs best. For example, I hear everyone say you gotta shift at the lowest rpm possible, but my car seems to do better on fuel when I shift at higher rpms! So, I guess it's all about having fun finding out for yourself. These days I try to shift at around 4 -5K all the time, just to see what I would get...

Interesting that you mention this, because I have some doubts about this argument. Actually I'm confused about it but maybe someone can shed some light...

If you want to accelerate as quickly as possible, you would delay shifting up as much as possible (without damaging the engine).

But that doesn't necessarily mean that shifting up as early as possible is going to be best for fuel efficiency, right? (although it will be best for reducing engine noise, wear and vibration)

To my understanding, the best for fuel efficiency is to run the engine at a constant rpm (and that's what the CVT boxes are good at), although wind resistance also plays a factor so above some limit (~60 km/h I think) you end up burning a lot of fuel to overcome wind resistance (but that has to be countered with how quickly you want to get where you're going).

Some questions:

If you change gears too often, doesn't that mean you're subjecting the engine to much wider rpm variations and hence more fuel burned?

Also, if you are shifting up early, then your engine is at low rpms and generally that's low power/low torque (?), so you may actually burn more fuel trying to accelerate the engine to a decent rpm in a high gear than if you had let it come to high rpms at a lower gear?

(i.e. accelerating a little less agressively may help save fuel, but if you overdo it then you just end up wasting fuel AND being slow?)

[jehan80]

While agreeing with what you have said, I think there's also situations where you really should be aware of your fuel efficiency - i.e. if you are getting much lower efficiencies than the norm for that model, (after correcting for city/outstation driving) then it's an indication to check if anything needs replacement/cleaning. Some things like underinflated tyres you can check regardless (assuming the driver knows what pressure he should be using!) but it can be a good reminder for things like injector cleaning / fuel system cleaning (anything that doesn't happen every service).

Or it could just be an indication that you need to change your driving habits!

btw why is this in the Mitsubishi forum?

Since you mentioned injector cleaning I thought I'll share my own experience. I have a vios that consistently did 9.5 kmpl. Did injector cleaning abt a month ago, and now the fuel economy is always around the 10.5 mark, which for me was unexpected.

[Wheel]

btw why is this in the Mitsubishi forum?

Ooops, im a newbie and didnt pay attention on where im posting

[harshansenadhir]

Some questions:

If you change gears too often, doesn't that mean you're subjecting the engine to much wider rpm variations and hence more fuel burned?

if change too often to stay in the correct RPM : Speed ratio, then that'll result in optimum fuel efficiency of the engine.

Also, if you are shifting up early, then your engine is at low rpms and generally that's low power/low torque (?), so you may actually burn more fuel trying to accelerate the engine to a decent rpm in a high gear than if you had let it come to high rpms at a lower gear?

(i.e. accelerating a little less agressively may help save fuel, but if you overdo it then you just end up wasting fuel AND being slow?)

yes, pushing the throttle more on a high gear will result in more fuel wastage. What's best is rev bit aggressively on low couple of gears and then achieve steady speed, say 60kmph, quicker (not with a wheel spin though) and then maintain it with lowering throttle on some intervals to let the autobox to shift up.

[Wheel]

yes, pushing the throttle more on a high gear will result in more fuel wastage. What's best is rev bit aggressively on low couple of gears and then achieve steady speed, say 60kmph, quicker (not with a wheel spin though) and then maintain it with lowering throttle on some intervals to let the autobox to shift up.

Yes, this is the exact way im working and that's y i think im getting figures like 13kmpl on N16 while most of the people r not believing me. I dont let the acc pedal to feel my push when im around 50-60kmph, just several millimeters push will rise you up to 80-85kmph within say, 15-20 seconds(not sure abt this figure, but it takes some time). I think it gives some rest to breaks too other than rushing to 80's and getting on break pedal in traffic, coz in this method it'll take 15-20 seconds to speed up so generally it should be a less traffic road to achieve this speed.

[MkX]

As I was thinking buying a Vios would give me a whopping 18kmpl fuel efficiency, and will make me more savings over my N16, just worked out the numbers as follows. Pls consider following robust numbers take ONLY fuel consumption into account. No depreciation or inflation is considered.

How mileage affects…

Vios Price = 2400000

N16 Price = 1800000

(a) If I buy Vios over N16, the extra expenditure = 600000

Vios fuel efficiency (at it’s best) = 18kmpl

N16 Fuel efficiency (at it’s best) = 13kmpl

I assume I run 1000km per month. Then monthly fuel consumption for,

Vios = 1000/18 = 55.6 ltrs

N16 = 1000/13 = 76.9 ltrs

Saving I have if I buy Vios = 76.9 – 55.6 = 21.3 ltrs * 115 = Rs. 2449.50 Per month

If I am to recover my extra expenditure at (a) by this monthly saving, number of months I have to run my Vios = 600000/2449.5 = 244.9 months = 20.4 years.

So, spending more 6lkhs for a Vios over N16 is profitable for me after 20 years!

I cant believe this is correct. Pls correct me if i've mistaken somewhere...

Your comments are welcome!!

1.OH GOD.. ARE YOU GOING TO USE SAME CAR FOR 20 YEARS.

2. Do you think you can get 18Kmpl from Vios ???? My ex boss has one and it does around 12 - 14 kmpl on average. Which means after in reality you will not save 6 laks after 20 years.

3. Waiting 20 years to cover the cost you spend over N16 (mind you that its not 6 laks profit after 20 years, but your cost will equal)

4. If you put that extra 6 laks on a fixed deposit for 20 years how much real profit you can earn at 10% average interest. After 20 years you will have minimum of Rs.3,669,545 in your account. Which gives you 3,069,545 or 3 Million real cash So you can spend your retirement peacefully. (some finance guy can help with exact interest amount here.. this is just average)

So the point if you take you desicion based on the calculations and assumptions you have done here.. it will be totaly lost interms of your so called profil (cost saving in reality).

How ever this does not mean N16 is better or Vios is better.. it is different matter to be discussed after all. However its just stupid to calculate expected cost saving over 20 years of time and take your desicion when buying a Car.

[heavyD]

To my understanding, the best for fuel efficiency is to run the engine at a constant rpm (and that's what the CVT boxes are good at), although wind resistance also plays a factor so above some limit (~60 km/h I think) you end up burning a lot of fuel to overcome wind resistance (but that has to be countered with how quickly you want to get where you're going).

Some questions:

If you change gears too often, doesn't that mean you're subjecting the engine to much wider rpm variations and hence more fuel burned?

Also, if you are shifting up early, then your engine is at low rpms and generally that's low power/low torque (?), so you may actually burn more fuel trying to accelerate the engine to a decent rpm in a high gear than if you had let it come to high rpms at a lower gear?

(i.e. accelerating a little less agressively may help save fuel, but if you overdo it then you just end up wasting fuel AND being slow?)

Yeah, it's all about measuring the distance, calculating speed and how quickly you wanna get there and so forth... can be tricky if you're looking for absolute efficiency, I suppose. My car does best in top gear at around 60 -70 kmph. But the occasional burst to 90 - 100 seems to be more forgiving than slowing down. So, I'd rather just get to 60 as soon as possible and try to stay there as long as possible.

I dunno about the rpm difference, but isn't the highest gear is the most economical (since you're already moving, you need only a light jab of the throttle to keep going). So I suppose shifting down is detrimental, or shifting all the time. More so on an auto since there is a bigger energy loss on an auto than a manual. (I'm no expert, just what I read off the net... )

[Sifaan]

So I suppose shifting down is detrimental, or shifting all the time. More so on an auto since there is a bigger energy loss on an auto than a manual. (I'm no expert, just what I read off the net... )

To my understanding, energy loss on an automatic transmission refers to output power vs. input power (there is a loss in the torque converter, and this is more than a clutch plate in good condition (i.e. not worn out and slipping)). I don't know if there is energy loss in the transmission owing to changing gears

[heavyD]

To my understanding, energy loss on an automatic transmission refers to output power vs. input power (there is a loss in the torque converter, and this is more than a clutch plate in good condition (i.e. not worn out and slipping)). I don't know if there is energy loss in the transmission owing to changing gears

Isn't that one of the primary reasons auto boxes have a higher fuel consumption rate?

[Sifaan]

Isn't that one of the primary reasons auto boxes have a higher fuel consumption rate?

well, AFAIK it's part of the story but I thought a bigger part of the equation is that gear changes occur at predefined rpms which is a balance between performance/wear/noise/comfort/economy etc. so then you end up flooring the pedal to get the pickup you want + fuel waste, or even otherwise it might have been better fuel-economy-wise to delay the shift up a little (but not so much that RPMs go too low)

Note: All I have written on this thread is an collection of what I have read in various places and posted in good faith... but it might be partly (or wholly) bullshit. you have been warned

[BLu3HaZe]

Thought to bump this thread for all the 'Fuel Consumption' maniacs around AL lately And good reasoning guys!!

[SpeedyAsA]

<!--quoteo(post=131329:date=Aug 31 2010, 11:14 AM:name=Wheel)--><div class='quotetop'>QUOTE (Wheel @ Aug 31 2010, 11:14 AM) <a href="index.php?act=findpost&pid=131329"><{POST_SNAPBACK}></a></div><div class='quotemain'><!--quotec-->As I was thinking buying a Vios would give me a whopping 18kmpl fuel efficiency, and will make me more savings over my N16, just worked out the numbers as follows. Pls consider following robust numbers take ONLY fuel consumption into account. No depreciation or inflation is considered.

<!--sizeo:5--><span style="font-size:18pt;line-height:100%"><!--/sizeo-->How mileage affects…<!--sizec--></span><!--/sizec-->

Vios Price = 2400000

N16 Price = 1800000

(a) If I buy Vios over N16, the extra expenditure = 600000

Vios fuel efficiency (at it’s best) = 18kmpl

N16 Fuel efficiency (at it’s best) = 13kmpl

I assume I run 1000km per month. Then monthly fuel consumption for,

Vios = 1000/18 = 55.6 ltrs

N16 = 1000/13 = 76.9 ltrs

Saving I have if I buy Vios = 76.9 – 55.6 = 21.3 ltrs * 115 = Rs. 2449.50 Per month

If I am to recover my extra expenditure at (a) by this monthly saving, number of months I have to run my Vios = 600000/2449.5 = 244.9 months = 20.4 years.

So,<!--coloro:#FF0000--><span style="color:#FF0000"><!--/coloro--> <b><!--sizeo:4--><span style="font-size:14pt;line-height:100%"><!--/sizeo-->spending more 6lkhs for a Vios over N16 is profitable for me after 20 years!<!--sizec--></span><!--/sizec--></b><!--colorc--></span><!--/colorc--> <img src="http://forum.autolanka.com/public/style_emoticons/<#EMO_DIR#>/action-smiley-060.gif" style="vertical-align:middle" emoid="" border="0" alt="action-smiley-060.gif" />

I cant believe this is correct. Pls correct me if i've mistaken somewhere...

<!--coloro:#00FF00--><span style="color:#00FF00"><!--/coloro--><!--sizeo:4--><span style="font-size:14pt;line-height:100%"><!--/sizeo-->Your comments are welcome!!<!--sizec--></span><!--/sizec--><!--colorc--></span><!--/colorc--><!--QuoteEnd--></div><!--QuoteEEnd-->

good point you're trying to make. However if you happened to run 2000km a month then the time taken to recover additional capital amount would be 10 years. Further if we assume the fuel prices are to go up in an exponential curve due to limitations in supply, this time duration would further reduce. Further, if Vios is newer than the N16, some maintenance costs too would have to consider and on the other side you have to consider the higher insurance premium for the expensive car, say Vios in this example.

This comparison can be done to vehicles of same class, but if you're paying more due to an upgrade, the value you pay on added comfort, luxury cannot be compared outright.

+1