[directinjection]

Roof carriers are said to increase air drag, adversely affecting fuel efficiency. Most Owner's Manuals advise you to remove the roof carrier after you have completed your journey. It may be a good idea to check your FE "before and after" to find out how far this is true!

Cheers!

[narayan]

Originally Posted by directinjection

Roof carriers are said to increase air drag, adversely affecting fuel efficiency. Most Owner's Manuals advise you to remove the roof carrier after you have completed your journey. It may be a good idea to check your FE "before and after" to find out how far this is true!

Cheers!

Seems this is true. Just did Chennai Cbe with an empty roof carrier because I would need it for the onward journey to Trivandrum. I got 12.8kmpl. This is against 15kmpl I've got earlier. The latter was with speeds of 90-100 but today I was in the 100-120 range. Still, even an empty roof carrier seems to be affecting FE by atleast 1-1.25kmpl. Am not very happy !

[YGarg]

Originally Posted by narayan

Seems this is true. Just did Chennai Cbe with an empty roof carrier because I would need it for the onward journey to Trivandrum. I got 12.8kmpl. This is against 15kmpl I've got earlier. The latter was with speeds of 90-100 but today I was in the 100-120 range. Still, even an empty roof carrier seems to be affecting FE by atleast 1-1.25kmpl. Am not very happy !

Drag force is proportional to square of speed, hence if you increase speed by 1.4 times your drag losses will be doubled (1.4 * 1.4 ≈ 2) ! On the other hand, this implicates that at lower speeds the contribution of air drag (to fuel consumption) is negligible. So before being unhappy with the roof-carrier, I suggest you to test FE in 90-100 kmph range again .

[kaviprem]

Originally Posted by narayan

Seems this is true. Just did Chennai Cbe with an empty roof carrier because I would need it for the onward journey to Trivandrum. I got 12.8kmpl. This is against 15kmpl I've got earlier. The latter was with speeds of 90-100 but today I was in the 100-120 range. Still, even an empty roof carrier seems to be affecting FE by atleast 1-1.25kmpl. Am not very happy !

Like YGarg mentioned, I have a first hand experience of this much of reduction in FE b/w the speed range of 90-100 and 100-120 KMPH.

Prem.

[condor]

Drag does affect FE, but in this case, the bigger culprit is the speed.

[ebonho]

So 90-100 is the sweet spot by general consensus for best mileage over long distance touring?

I know there have been experiments done by the Expressay authorities that proves that driving 80 kmph (Expressway speed limit) versus driving 120 kmph, the actual difference in time of arrival at the other end is just 15 minutes.

Point to ponder for the heavy foots (like me .....)

P.S. I am now getting 11+ kmpl ( around 180-185 kms for every 1000 buck refuel) in the city commute with A/c (albeit less now due to winter) compared to the 9-9.5 kmpl I was getting earlier. Purely by changing to driving truck style!

[narayan]

In the midst of a long trip the Odo crossed 8000kms. Should touch 9000 by the time I am back in Chennai.

Had a nice drive from Vechoor to Trivandrum in Kerala through the MC Road.

The key highlight of this leg of the trip was that the road is full of twisties with changes in road level also. So you come across fast left/right handers with the road rising up/down. Most stretches are just single lane ( on one side ). Hence it was a pretty good test of the Storme's handling which I would presume is far better than the Dicor. I was driving with a decent amount of luggage in the roof and still it was not so difficult getting the beast to take fast sweeping turns at 80kmph + speeds. The fact that the beast was fully packed inside could have helped in that planted feel as well.

Need to check FE tomorow/day after post tanking up. I am assuming I would have got a bit better than the figure I reported a few posts earlier since speeds were in the 50-80kmph range

Bye for now with some nice pictures from the resort I stayed at.

http://www.periyarriverlodge.com/index.asp

You can see the river Periyar in the background and this lodge is about <50ft from the water. Must visit for wildlife enthusiasts

In the first pick you can see the beast all loaded up. Managed to get 3 small trolley bags + 1 big one + 1 normal soft bag. Total weight should have been ~ 60kgs.

[F150]

Originally Posted by narayan

In the first pick you can see the beast all loaded up. Managed to get 3 small trolley bags + 1 big one + 1 normal soft bag. Total weight should have been ~ 60kgs.

Hey Narayan,

I have been silently monitoring this thread and I was not posting since I didnt have anything to add.

I wanted to ask, how many people were in the car ? Was the last row also occupied.

I think roof carrier is spoiling the looks of the beast and the air drag is too much, when you drive with the configuration in the first pic.

[narayan]

Originally Posted by F150

Hey Narayan
I wanted to ask, how many people were in the car ? Was the last row also occupied.

I think roof carrier is spoiling the looks of the beast and the air drag is too much, when you drive with the configuration in the first pic.

Hi F150
We were 4 adults + 3 kids. Last row was also full of luggage + 1 kid. Reason for so much luggage - out of the 7 ppl in the car 3 were women and 3 kids!

With luggage loaded up, you are right - the looks and aerodynamics are compromised. With the plain roof rack, it looks kind of ok - I got a lot of attention when the beast was moving around with just the roof rack - think the protruding 2 rods gives it a nice look.

[narayan]

Some clearer pictures

[apachelongbow]

For those of you who are interested, I conducted a small experiment a few days back. I had an OBD2 compliant scanner with me for a few days, so decided to test the scanner on my truck.
Amongst other things what struck me is the amount of power required (load on the engine) at low speeds versus high speeds.
What I found was the engine was loaded about 25-27% at speeds till 80kmph and at speeds between 100-120kmph the engine load went up to 60-65%. These loads are measured on an empty car, full fuel tank, air-conditioning on, 5th gear, constant speeds.
So what I gather, is that at higher speeds (greater than 100kmph) the engine load due aerodynamic drag increases disproportionately in brick shaped SUVs and causes at-least 2-3kmpl increase in fuel consumption.

[subraiyr]

Apologies for hijacking your thread. I just havent had time to start my ownership thread. Will do so shortly thanks to holiday season. In the meantime, went on a quick getaway in the mountains (coonoor, Wayanad) and the vehicle performed admirably. The only thing i noticed during the trip was that on climbs the vehicle did need downshifting compared to my earlier vehicle. This might be because i am transitioning from a petrol head to an oil burner and from a hatchback to an suv

Does anybody feel the difference on this

[narayan]

Originally Posted by subraiyr

the vehicle did need downshifting compared to my earlier vehicle. This might be because i am transitioning from a petrol head to an oil burner and from a hatchback to an suv

Does anybody feel the difference on this

Yes- this has been discussed in the official thread as well. Diesel + Turbo means you will run out of breath uphill if ur not in the turbo zone.

[subraiyr]

Originally Posted by narayan

Yes- this has been discussed in the official thread as well. Diesel + Turbo means you will run out of breath uphill if ur not in the turbo zone.

What then qualifies as turbo zone. I was at about 2500rpm + on certain areas and touching 3000rpm in certain climbs. Overall, this did reduce my fuel consumption, but on tank to tank with 100% ac i did manage to eke out 11.4kmpl. I think that does qualify as a good standard

But then again, the Storme owners are never worried about mileage. It is all about the truck

[narayan]

Originally Posted by subraiyr

What then qualifies as turbo zone. I was at about 2500rpm + on certain areas and touching 3000rpm in certain climbs. Overall, this did reduce my fuel consumption, but on tank to tank with 100% ac i did manage to eke out 11.4kmpl. I think that does qualify as a good standard

But then again, the Storme owners are never worried about mileage. It is all about the truck

I am doing a Yercaud trip in Jan for 2 reasons - to make use of my club mahindra quota and push the beast past 10k - kms ( will be the fastest 10k for me in any of my cars so far ). Will update you on how the beast performed. I am not too happy to hear the FE numbers you posted.

But how was the braking downhill ? I personally feel the Storme brakes are not adequate - or atleast the initial bite is lacking. It feels spongy initially and then when you press it hard, you start feeling the braking action.