Roofrack fuel consumption

A few months back i replaced my roofrack with a funky one with folding ladder and also bought a set of 265/75 r16 mud terrains.
Anyhow my defender 300tdi mpg dropped to 21 mpg?? I thought at first it might be the tyres but having removed the roofrack it's back to 28mpg!!!!
I know roofracks might affect mpg by about 5-10% but not over 25% !!

I heard that a rack took 12% off, but i get 19 to 20mph with a patriot rack and 285 BFG's on, but I believe its more than that 12%, so it might be right.
Plus my mate put a rack on his disco2 and the fuel went down a huge amount.

Sounds about right. My 110 had a huge great rack on when I got it and it'd only do 55 or 60 on the flat. Does 70 without it no problem. Never really checked the fuel consumption before I took it off but it makes sense that it's way better without it.

Do what I did, chip it, intercool it, and not give a toss bout the fuel.

wonder what it will be like with my rack and new roof tent

shadowster

depends on what speeds you do though dunnit? ive just fitted an ARB rack and rooftent to my N/A but i only do 55 on the M4 so i doubt its going to make much diff.

Jeeezzz, never go over 70mph, if you do, you can really see the fuel needle go down.

Don't forget that fitting bigger wheels effectively makes the "miles" in MPG shorter so will skew the figures! Also makes the miles in MPH shorter so the speedo will tell you yer going slower than you actually are.

Checked with GPS, speedo is bang on the exact speed.
Checked distance with GPS and 39 GPS miles were 37 miles on the odometer.
Basically the roofrack even unladen was losing me 25% efficiency mainly used on 30/40 mph roads. It feels a bit nippier too!

Griffdowg said:

depends on what speeds you do though dunnit? ive just fitted an ARB rack and rooftent to my N/A but i only do 55 on the M4 so i doubt its going to make much diff.

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hi griffdowg
any plans for using your roof tent this year
mines aint out the wrapper yet
hoping to get a motorbike trailer hitch up the bike do a bit of touring

shadowster

yer, over the bank hols for 10days across wales, numerous camping trips through the summer then 4weeks in Morocco