Don't like the adverts?  Click here to remove them

Fuel consumption

Graham

Well-Known Member
Joined
Mar 22, 2010
Messages
3,981
Garage
Country Flag
uk
Hi all,

We just done a trip to Paris and back
332 miles.
Used 50.29 liters
Which is close to 11 UK gallons
Worked out at 30.18 mpg

Cruise control set to 95 - 97 km/k (60 mph)

BFG All Terrains 265 x 70 x R17
Front 34 psi
Rear 36 psi

The star-ship is running beautiful

Gra
 
Driving at 95 - 97 km/k (60 mph) that distance would send me to sleep......
 
Some times, fuel costs are more important than time.
It's been a few years since I was able to do an accurate "brim to brim" calculation.

I would have liked more, sure, but I am sure the slightly oversize tyres, suck a couple of mpg.

Any way, 30 mpg is OK for me.

Gra.
 
averaged 30mpg on my last long run aswell, running similar pressures on those horrendously terrible dunlops pretty consistantly at 80mph
 
Do you mean you got 30 mpg at 80 mph ?????

Gra
 
Don't like the adverts?  Click here to remove them
Do you mean you got 30 mpg at 80 mph ?????

Gra

on a return trip to the UK driving manily on motorway I averaged 30mpg for the entire journey. While on the motorways I tried to keep her at 80mph as much as possible but obviously there were smaller amounts of driving on other roads at lower speeds too but in fairness they were minimal.
Tyre pressures were ~36psi all round which can be a little harsh ridewise but I'll take the economy on a long trip like that. I was reasonably well loaded too. Weather was cool but dry with little in the way of winds.
I was pretty happy with that and that was in a manual which has a slightly lower top gear than the auto I think.

Dont get me wrong, I normally dont see 30mpg, its only on a long run (as you said) that I get the chance and I dont honestly think I'd see an instantanious 30mpg figure normally at 80mph . The only time I've seen 30mpg is on two trips to the UK where I did 500miles + each time.
Day to day its more like 25 to 27mpg which I dont think is too bad considering the weight. I know people driving similar size vehicles who have been saying for years that they get 40mpg average on longer runs, I dont believe them !

Theres another thing, one trip I had a roof box, the next trip I didnt. Both trips were similar miles, similar speeds, terrain & weight, both trips returned same economy. So I dont think my roof box make a blind bit of difference economy wise ! ........... carparks are a different matter.
 
Hi all,

We just done a trip to Paris and back
332 miles.
Used 50.29 liters
Which is close to 11 UK gallons
Worked out at 30.18 mpg

Cruise control set to 95 - 97 km/k (60 mph)

BFG All Terrains 265 x 70 x R17
Front 34 psi
Rear 36 psi

The star-ship is running beautiful


Gra

Sounds good to me Gra. I'd be happy with that. When I use the Land Rovers I stick at that speed and only get 25mpg :clap:
 
My life is way too short to worry about saving one tank of diesel on a long run!
 
My life is way too short to worry about saving one tank of diesel on a long run!
.
.
Hi Andrew,

I know where your coming from.

But thereis a difference to a "long run", and a "LOOOONG RUN"

On our recent jaunt around Europe, we must have clocked up some thing like 4000 miles.

A tad more than saving just one tank of diesel.

So in this respect, it was worth it for us to lower our speed a bit, after all, we had 4 months in Europe, so no rush at all :icon-biggrin:

Gra.
 
I might be wrong :icon-biggrin: but if stock size is 265 x 65 x 17

Aren't you slightly better off due to your tyres being 3.48% bigger
in diameter than stock so you'll actually have travelled further than
the odometer says thus your mpg will be 3.48% better

I shall wait for my maths to be blown apart by someone :doh:
 
Last edited:
All things being equal, you need "x" amount of liters, to travel "x" amount of km.

Sure I may go further on each revolution of the tyres, but it also costs me more fuel to turn these bigger tyres.

Fuel consumption generally drops a little when fitting larger tyres.

Actually, the 265 x 70 x R17 tyres, bring teh speedo, and milometer to 100% accurate, where as the 265 x 65 x R17 (stock) tyres over read.
eg at a speedo indicated 60 mph you are only doing 56-57 mph

Gra.
 
I agree its not an exact science as the bigger tyres are heavier plus as you point out
it looks like the speedo would appear to be out by the 3.48% difference in tyre diameter.

Oh well it was worth looking at :)
 
I've come to a conclusion that all speedos are inaccurate, but there is a speed where it's probably spot on.

I have bigger tyres than stock and on checking my speed with GPS I find it spt on at about 80kph.

At speeds lower than this the speedo reads marginally over and at speeds greater than 80kph the speedo reads under.

Therefore the bigger tyres has simply shifted the "accurate point" along the scale.

It's said that the most accurate time clock is one that doesn't work, it's spot on twice a day and useless at other times. A speedo may not be spot on all the time, but it's a useful guide...:lol:
 
Last edited:
Yes they're never going to be spot on, tyre wear for one reason

I was interested purely from the economy point of view as i was looking into getting
one of the plugin boxes that Lindop sell, after doing the maths if i got 10% better
economy it would take too long to pay for itself as i don't do enough miles in a year.
 
Fully loaded and doing LOOOONG Runs I get 22mpg on Tarmac and in low box it varies between 15 to 18mpg dependant upon surface and steepness.

If vehicle based expedition is your thing then worrying about a couple of tanks of diesel is pointless, personally if you budget a tank of fuel every 300 miles that will probably give you a reasonable fuel cost target.

As off-roading fully loaded is fairly severe duty, I always allow for a £1000 local repair, because you never know what you may hit or break and need to fix locally.

Over size tyres dont always improve economy as they are effectively changing the overall gearing and can increase engine loads and make gearboxes change down prematurely, both of which use more fuel.

It's also worth noting that under load a change down will make your engine rev more freely increasing oil pump circulation and coolant circulation, reducing long term wear and tear on your engine and transmission at the sacrifice of immediate fuel economy but maybe saving long term maintenance costs.

All that said.... If I had to drive 4000 miles at 50-60 mph I would be knawing the steering wheel with my teeth in boredom ! And if you want to tour with economy buy a Yaris !
 
After doing 4500 miles on recent Morocco trip, we were cruising at 60-65ish on a couple days on the run back through Spain as we werent in a rush and the distance was short'ish for the day.
but often i find spending that hour or so in the day in the car, due to driving slower, exhausting if i have to reach a particular destination that day
once back in UK though, I though F^%^&-it and put foot down as we just wanted to get home = 20mpg :)



i think having taller tyres (2" taller) = (6% difference in speedo/odometer ) on my LC caused engine to run hotter, and before i fitted a transmission cooler, the autobox used to get hot in mountains.
and i had to keep an sharp eye on my VDO coolant and transmission temp guages driving in the sand climbing dunes

i think my Yaris would die horribly if i loaded it with the kit the LC carrys :lol: :lol:
 
Last edited:
i think my Yaris would die horribly if i loaded it with the kit the LC carrys :lol: :lol:[/QUOTE]

Yea but the money you save on fuel you could spend on hotels :)
 
Depends on the travelling companion you have. :icon-wink:
 
Back
Top