[rahul_intlad]

A few thoughts from a non-technical guy so forgive me if I am wrong:

1>. Does mileage[FE] not decrease after upsizing of tyres?

2>.Could be the heat factor as well,the temperature is very very high nowadays,so AC has to work that much more.Also arent we having a thread Does temperature affect Fuel Economy?

[ess_a]

Hey ScarySkulls, there might be several reasons that were pushing down your milega (Wider tyres (marginally), load and the merciless heat). BUTT 14.5 kmpl that too on a highways is seriously very low for an Alto. Is that an 800 cc one na??
Even in worst traffic condtts of Delhi with 100%AC, the lowest I have got is 16.2. I normally use Power.
Do get this checked at a MASS. ASAP.

[CrAzY dRiVeR]

Originally Posted by rahul_intlad

A few thoughts from a non-technical guy so forgive me if I am wrong:

1>. Does mileage[FE] not decrease after upsizing of tyres?

2>.Could be the heat factor as well,the temperature is very very high nowadays,so AC has to work that much more.Also arent we having a thread Does temperature affect Fuel Economy?

Isnt that thread- Does fan speed affect fuel economy?

[xinome]

i get 22 km on the highways doing 100 or 110, my top speed on the car downhill was 140, on straight lanes i get to touch 135 max.
plus i also have a freeflow exhaust and a k&n stock replacement.

in the city i just cant help myself with the sound of the beautiful exhaust so i rev and rev so i cant help you with city mileage but i get 22 on the highways 5th gear without a/c and speeds upto 100.

plus i also know it can go higher if i can drive the car more economically

[pogusingh]

Originally Posted by pogusingh

When I read the title <woes>; I thought you are getting something under 10 kmpl
I think its perfectly ok to get 14.5. You can check with other fellow members who have alto and I think this much average is pretty ok

Hmmmm, I think 14.5 in light of the above posts looks really low; how did you really measure it scary skull?

[ScarySkulls]

When about to start trip, Tank up. That means 35 Litres now in the tank. Set trip meter to Zero.
After the trip, tank up again and divide the no. of kms shown by the trip meter with the amount of fuel that goes in.

Fairly Simple. Isnt it?

[kamy450]

My Alto gives me 16 in city and 19+ on highway with 90 % Aircon.

You need to touch base your service station. The mileage which u get from alto is less to my knowledge.

Are you sure about petrol bunk from where you fill petrol? how about a change and then measure your mileage?

[ScarySkulls]

I'm sure the petrl bunk is a good one. But anyways, have changed this time just to check.

[theMAG]

You folks are piling on too much expectation from an 800 cc car that already far outperforms and overdelivers beyond its own physical limitations.

[rks]

Originally Posted by ScarySkulls

Hi guys.
I got myself an almost new Alto from brother.
Feb 07 model. 7k run when I got it. (now 8.5k). (first three free services done)


Avg calculated was around 14.5kmpl.

The above figure is with 100% A/C on City or Highway. Basically every possible moment the car is switched on.
Tyres are 155/65 R13 Michelin XM1 on League 5.5J rims.
Passenger weight (for highway run) --> 250kg ATLEAST + bootful of luggage.

I feel the fuel economy that I got is on the low side.

I must however mention that sometimes during highway use, I used to get this funny sound from the underbody. Like the axle scrapping or something.
Example of the sound can be...like trying to run the car with hand brake applied. It made that kind of metal grinding noise.

The above sound description is just as an example and I couldnt find the source of it.

Please help on the following two topics.
1) Fuel Economy
2) Possible reasons/sources of sound.

Regarding FE. If your pick-up is above normal, you can get the engine tuned for improved mileage; your pick-up may drop a little. Plius your AC may be drawing too much power as mentioned by others; you can check the mileage without AC to verify that your AC is OK.

But I feel that your rims are too wide (5.5 J against 4J stock) plus wider tyres (155 mm versus 145 stock). This will increase the contact patch and will improve pick-up and handling (with a harsh ride on bad roads), but FE and top speed will come down. Note also that as per Michelin Australia, the maximum rim width allowed for 155/70-R13 tyres is 5J and the optimal rim width is 4.5J; see the following website:

Michelin Australia

155/65 size is not mentioned here, but we may assume the same holds. Wheras the carbibles website allows up to 6J maximum for 155 mm tyres. Since you are using Michelin XM1 tyres, I think you might have been better off with 4.5 J or max. 5J as per their recommendations. Michelin tyres are very grippy and using wider rims may bring down FE (but of course you will get great grip and handling with your wheel/tyre combination).

Your 30 psi tyre pressures look OK, but you could check the tyres for any slow punctures. Monitor the tyre pressures initially once a week to see if there is any noticeable drop in pressure. Tyre pressures should be set/checked when tyres are cold (say first thing in the morning). A substantial drop could bring down FE significantly.

Do not ignore the occasional noise that you are hearing. It could well be fouling of your wheels/tyres with either the suspension/steering components, brake callipers or the wheel well, say upon turning or when the car is on rough roads. You fully loaded car plus the high rim width of 5.5 J increases the possibility of fouling, especially if the rim offset is not correctly chosen. There will not be much tyre sidewall bulge in your case and the wheel could be directly touching somewhere. My suggestion is to carefully check the various clearances, including while turning and also from the underside of the car, so that you can at least have peace of mind. Plus check the inner sides of the rims/tyres for any scraping marks.

[chetanhanda]

Originally Posted by theMAG

You folks are piling on too much expectation from an 800 cc car that already far outperforms and overdelivers beyond its own physical limitations.

perfect !! it does quite a lot

that small 800 cc 4valve head with 5 speed easily goes above 22+ on highways... 14kmh is too low for highways...
I had the same engine in my maruti 800 (not alto) and 14 was acheivable in city with a light foot, no AC no power steering and freeflow exhaust..

get ur car checked properly... there is something seriously wrong...
hows the power ? does it feel sluggish also ? or has just the mileage gone down ?

[pogusingh]

Originally Posted by ScarySkulls

I'm sure the petrl bunk is a good one. But anyways, have changed this time just to check.

During the trip; did you notice the following
1) Pick-up with AC to be very sluggish
2) Engine making a lot of sound before it comes to life in 2nd/3rd gear
4) Did you have to push the accelerator hard to keep the vehicle in constant speed?

[Vid6639]

There's a weight difference of around 70-80kgs compared to 800.

In city with AC i get just below 13kmpl. I have got everything checked, fuel filter, air filter, valve clearance, clutch, idle rpm, spark plugs cleaned.

The car does not feel sluggish at all, it's just the mileage which is really bad even in my case. I generally drive with a light foot with minimal use of the clutch.

[ScarySkulls]

Originally Posted by rks

Regarding FE. If your pick-up is above normal, you can get the engine tuned for improved mileage; your pick-up may drop a little. Plius your AC may be drawing too much power as mentioned by others; you can check the mileage without AC to verify that your AC is OK.

But I feel that your rims are too wide (5.5 J against 4J stock) plus wider tyres (155 mm versus 145 stock). This will increase the contact patch and will improve pick-up and handling (with a harsh ride on bad roads), but FE and top speed will come down. Note also that as per Michelin Australia, the maximum rim width allowed for 155/70-R13 tyres is 5J and the optimal rim width is 4.5J; see the following website:

Michelin Australia

155/65 size is not mentioned here, but we may assume the same holds. Wheras the carbibles website allows up to 6J maximum for 155 mm tyres. Since you are using Michelin XM1 tyres, I think you might have been better off with 4.5 J or max. 5J as per their recommendations. Michelin tyres are very grippy and using wider rims may bring down FE (but of course you will get great grip and handling with your wheel/tyre combination).

Your 30 psi tyre pressures look OK, but you could check the tyres for any slow punctures. Monitor the tyre pressures initially once a week to see if there is any noticeable drop in pressure. Tyre pressures should be set/checked when tyres are cold (say first thing in the morning). A substantial drop could bring down FE significantly.

Do not ignore the occasional noise that you are hearing. It could well be fouling of your wheels/tyres with either the suspension/steering components, brake callipers or the wheel well, say upon turning or when the car is on rough roads. You fully loaded car plus the high rim width of 5.5 J increases the possibility of fouling, especially if the rim offset is not correctly chosen. There will not be much tyre sidewall bulge in your case and the wheel could be directly touching somewhere. My suggestion is to carefully check the various clearances, including while turning and also from the underside of the car, so that you can at least have peace of mind. Plus check the inner sides of the rims/tyres for any scraping marks.

rim size is a tad on the higher side. I will agree on that. Even I feel that 5J was perfect. But brother got 5.5J (dont know why the hell).

Monitoring tyre pressures from tomorrow on when my digital gauge comes back to me.

Offset, camber etc are pretty ok and rims balanced.
Will check for the fouling part though because did hear funny sounds.
Wheels or tyres are not fouling anywhere, I have checked that.

@ PoguSingh --> Nope buddy. None of these factors were noticed.

[ScarySkulls]

Originally Posted by theMAG

You folks are piling on too much expectation from an 800 cc car that already far outperforms and overdelivers beyond its own physical limitations.

And what is that supposed to mean exactly?