Canopy affecting fuel economy

[tryhard]

Hi guys

I drove about an hour today to the nearest Flexiglass outlet to get the tub liner and canopy fitted. On the way over I was watching the Triton computer fairly closely and it stayed on 9.5 - 9.6 litres/100 km the whole way.

On the return journey, it immediately jumped to (and didn't budge from) 10.1 litres/100 km. I realise the computer might not be super accurate but as its the same measure used on the way over, figure it's not a bad comparison.

Then I wondered if the extra drag would cause it, and when I looked at the canopy and how its fitted, the over-the-lip tub liner and two strips of fairly obvious foam must add a reasonable amount of height :



So when I looked more closely at the part of the canopy facing forwards toward the wind, it looks like a pretty big air dam to me :The top of the canopy is 40mm above the rear roof of the cab :



Compared to the higher middle part of the cab, as you can see from the front shot, it's just about dead level :




But I'd reckon the air coming over the curved cab would get shot straight into the kind of top lip of the canopy. I've been told plenty of times I'm no rocket scientist, but I would have thought if the canopy was level with the rear of the cab there would be way less drag.

Initially I was happy enough with the look of it from a distance, but as the photos in shed profile show, up close the foam and overall fitting doesn't look the best :



If you're 10 feet away, it looks fine, and my eyesight's crappy anyway so after some time I will probably get used to it. But the pics I have seen of ARB gear fitted looked a lot cleaner as far as I could tell, and I'm not sure why new gear specifically made for an exact vehicle needs foam packers - but maybe I am just a fussy bastard. I haven't seen a TJM one fitted so unsure how it compares to Flexiglass. I'm going on the hunt for some more utes with canopies to compare on the weekend, because admittedly I have never paid much attention.

What does everyone reckon ?
a) Is the fit reasonable or should I be requesting the installer to make the canopy more level with the rear of the cab somehow (maybe remove some foam or the tub liner I guess) ?
b) Is the increase in fuel consumption of about 0.5 litres per 100 km normal once a canopy is fitted ?

Thanks for bearing with this massive pain in the a### newbie

Cheers
Carl

[Urshtnme]

Hey Carl! mate I've found that the weight in general of the canopy does add to the fuel consumption a little. There looks like to be a touch of wind resistance there as well. Just wait till you add on the bar work, winch, roof rack etc etc. I'm currently getting between 12.8 and 13.5 lt per 100kms with the Turbo Diesel auto.

[lfunkqe]

im consistantly reading 9.6l /100km with canopy but no tub liner so the fit is a little different

[tryhard]

Thanks blokes Big variation in fuel consumption eh !?

Do your canopies sit above the rear of the cab as well ? I would think if I just removed the foam I could improve it a bit, but I imagine that is meant to take up any flex - so possibly would affect the warranty, but it just looks a bit of an after thought - maybe they have had a few crack as someone mentioned to me elsewhere, and the foam is to minimise canopies being returned broken

[lfunkqe]

im wondering if its due to the fact that you have a tub liner that sits over the lip which affects the fit of the canopy?

[greybeard]

quick way to check if it's wind drag would be to make a fairing with cardboard and duct tape between the canopy and roof.
easier than trying to get the foam tape out just to see.

[andyj]

I have the mitsi canopy from day 1 but if it had looked like that it would have been back and I have the over lip liner

Andy

[schimno]

Wow.......such a huge increase in fuel economy..what can I say.. ...
Okay I don't say much on this forum...but come on... people add this, add that...some things gotta give.. I'd love to be able to add a canopy, suspension, tyres etc etc...however more important things in life..I'm lucky I even managed to get a ML Triton....As I've said before "love My Triton faults and all"...Just a spit, maybe frustration more than anything... no offence intened to any one....

[tryhard]

Wow.......such a huge increase in fuel economy..what can I say.. ...
Okay I don't say much on this forum...but come on... people add this, add that...some things gotta give.. I'd love to be able to add a canopy, suspension, tyres etc etc...however more important things in life..I'm lucky I even managed to get a ML Triton....As I've said before "love My Triton faults and all"...Just a spit, maybe frustration more than anything... no offence intened to any one....

Spit away mate - no offence taken here. Actually the fuel economy issue doesn't bother me too much (I reckon it equates to about $200 per year in extra fuel) ... probably more keen to get people's thoughts on the fit and finish of the aftermarket product listed as a 'fit' for the Triton, which I'm not sure I'm rapt with - given it cost a couple of grand ...maybe I expect too much but money doesn't grow on trees ... anyhoo thanks for your comments regardless

[Greedy]

Tryhard, I'd be back at them big time. That stripping they have used looks no good at all. As you say, good money has been paid. Make sure you get a better finish than that. Surely, there is a rubber seal they could use similar to door rubbers that would make it look a heap better.

[tryhard]

quick way to check if it's wind drag would be to make a fairing with cardboard and duct tape between the canopy and roof.
easier than trying to get the foam tape out just to see.

Great idea mate - tomorrow the Triton might look a bit 'special'

[tryhard]

Tryhard, I'd be back at them big time. That stripping they have used looks no good at all. As you say, good money has been paid. Make sure you get a better finish than that. Surely, there is a rubber seal they could use similar to door rubbers that would make it look a heap better.

Cheers mate - in the cold light of day today it does look bloody awful. I'll give 'em a call and see whether this is what a typical fit of a Flexiglass canopy to a Triton has to look like. If so, I don't reckon I'd recommend them if appearance is an issue. Will post how I go

[ratstriton]

Hey tryhard
I have just had an arb canopy fitted to mine and if it had looked liked your canopy when i pcked it up I would have told them to take it off.
But I think the the problem with the fit is due to the tub linner as I think the design of the canopy is to sit directly on the tray.
sorry if my comment's seem strong but you have nice looking truck with a poor fitting canopy, I would be ringing the company straight away and getting it sorted.
Tim

EDIT (Just looked at your profile I didn't know it was flexi tub linner, you would think they would have designed it so the canopy would mount up to it better.)

[tryhard]

Hey tryhard
I have just had an arb canopy fitted to mine and if it had looked liked your canopy when i pcked it up I would have told them to take it off.
But I think the the problem with the fit is due to the tub linner as I think the design of the canopy is to sit directly on the tray.
sorry if my comment's seem strong but you have nice looking truck with a poor fitting canopy, I would be ringing the company straight away and getting it sorted.
Tim

EDIT (Just looked at your profile I didn't know it was flexi tub linner, you would think they would have designed it so the canopy would mount up to it better.)

Hey Tim

Thanks for the comments mate. I can be a bit of a pain in the ar$e so I was worried I was being too fussy, but the pics I have seen of ARB, CarryBoy, TJM and Mitsubishi fitted all look a lot better than the one on mine. I went for the Flexiglass Tub Liner because like the canopy it said it would 'fit' the Triton, and the more I look at this thing the more I think it doesn't actually fit. There's not really much excuse on Flexi's part because they offered it as a package to suit Triton and 2 strips of packing foam to make it actually sit on there isn't a great approach.

I'll call the guys who fitted it Monday and if no joy talk to the WA head office, because all their brochures etc. seem to support the quality of their brand, and I'm hoping in this case I might just have copped poor fitting method and it can be sorted out. I'll ask them to either make it look like the brochure and reduce the height above the cab, or take it back. Maybe they will fit better without their tub liner, but I'm kind of stuck with the tub liner now as its drilled in a few places by their fitting. The tub liner does seem to follow the contour of the cab ok, its the canopy that seems more out of whack (because the foam is compressed in some spots and expanded in others. If I get stuck with the tub liner I hope another better fitting canopy might work - maybe ARB. I wasn't going to spend the extra dough, but I can see now it would have been better biting the bullet than naffing around like this !

Thanks for suffering through this

[tryhard]

quick way to check if it's wind drag would be to make a fairing with cardboard and duct tape between the canopy and roof.
easier than trying to get the foam tape out just to see.

Mate

I find it a bit hard to believe how well it worked ... but
With the pauper's aerofoil (waxed cardboard and gaffer tape!) filling the gap between cab and canopy, consumption dropped to 8.8 l/100 km. I took it off and it went back up to 9.8 for the same road and driving style, and so far hasn't revisited the 10.1 from before. (this was up to 60 km/h in 4th on a few km of local road, with air con on (vehicle still only done a few hundred km so guess figures will get worse as its run in, maybe)

Thanks for the idea though ... it definitely looks like the aerodynamics could be a lot better

Cheers
Carl

[Install]

I can immediately increase my mileage rates from 13L/100km to well under 10L/100km within seconds easily!...... i just unhook the 1800kg trailer i tow daily.

Seriously, with each additional "Sticky outy thing" i.e canopy, roof racks, ladder racks, pipe carriers and a full set of work gear (ladders pipe etc.. ) mpg drops in steady increments.
I just that's life for a tradie

[tryhard]

I just that's life for a tradie

Ah yes, but I haven't done a hard day's work in my life. The biggest sticky-outy thing I ever installed was the missus, and she chews up a bucketload more cash than anything I could spend on diesel

[greybeard]

I find it a bit hard to believe how well it worked ... but
With the pauper's aerofoil (waxed cardboard and gaffer tape!) filling the gap between cab and canopy, consumption dropped to 8.8 l/100 km. I took it off and it went back up to 9.8 for the same road and driving style, and so far hasn't revisited the 10.1 from before. (this was up to 60 km/h in 4th on a few km of local road, with air con on (vehicle still only done a few hundred km so guess figures will get worse as its run in, maybe)

Thanks for the idea though ... it definitely looks like the aerodynamics could be a lot better

Cheers
Carl

where's the pics?

[tryhard]

where's the pics?

You asked for it ...



I'm thinking of selling these kits on eBay - I can make a profit at $33 per kit plus fitting - the clear tape used on the deluxe model shown above might cost extra. Mind you, they are only any good for anyone else whose canopy sticks out over the top like dog's whatsits

[Blue]

Flexiglass canopies ALL have the same join up front and it has ALWAYS looked crap... A mate with an identical MK to my oldie had the flexiglass and I had the ARB - on a trip to our rural property (525km return) he averaged 2L/100 more consumption that mine with the ARB. It's not a great deal of fuel but the bottom line is it's absolutely unnecessary... He ended up making his own glass aerofoil which he adhered to the back of the cab with 3M double sided tape, it made a world of difference. It sat about 25mm over the joint in the canopy and was elevated approx 10mm above the canopy to allow for the independent movement of the tub.

[greybeard]

i've got a 2nd hand flexiglass on my MK and it is a pretty good fit.

[tryhard]

Thanks Blue - maybe I should spend a bit more time on my aerofoil - even though I am still intent on getting rid of the foam packing tape Greybeard - yours looks an excellent fit. I reckon what has thrown them is the curves on the new tubs - which would be a pain - maybe the mould doesn't quite allow enough creative swooshing - or maybe the combo of the tub liner and canopy accenuates the problem. Either way, if mine fitted like yours I'd be much less whingey
Cheers blokes

[Blue]

i've got a 2nd hand flexiglass on my MK and it is a pretty good fit.

That's a good fit greybeard, best I've ever seen from a Flexi - my mates sat much higher than that and on an MK also...

[ratstriton]

Thanks for the comments mate. I can be a bit of a pain in the ar$e so I was worried I was being too fussy, [/quote]

Hey tryhard
I'm like you mate when I pay for somthing with my hard earned I expect it to be right.

[greybeard]

i've got a 2nd hand flexiglass on my MK and it is a pretty good fit.

That's a good fit greybeard, best I've ever seen from a Flexi - my mates sat much higher than that and on an MK also...

it was a mid to late '90s mk that the canopy was fitted to. i picked it up from a wreckers for $400.
i replaced all of the seals around the windows ( $0 from the nice man at flexiglass )
i don't have a tub liner, just drawers and storage bays in the back.
i'm pretty happy with the fit. it just bolted straight on.