Puma Fuel economy on larger tyres

[cal415]

Hi All,
I am planning on running 255-85-16s or 285-75-16s on my 130, i would probobly run the standard size for general road use, but would like to get an idea of how much the bigger tyres have affected fuel economy. Does anyone run these sizes on the puma's and how much change did you see in economy? So far i am only on my 3rd tank of fuel and i am seeing about 600-650 from a tank filling about 67-70L each fill.

[Disco_owner]

Hi Mick ;

It's a Nice truck you got yourself :cool: , I do Like the Colour :) from your figures the puma is getting about 10.3/100Km. I couldn't tell you what 255/75/16 's would have on the fuel consumption , but wouldn't you factor it how heavy the vehilce would be at the time? how many passengers ? and how hard you are on the pedal ? :twisted:

[Tombie]

255s will be better for economy than the 285s by quite a margin...

I remember mine were :cool:

[PAT303]

Your doing well to get 600/650k's from a tank,mine see's 550 at best.My Tdi used more fuel going from 235's to 255's but it works harder than the Puma. Pat

[Drover]

I am just about to up grade tyres. Can't decide between -

265x75x16 MT BAJA MTZ's, 32inch in the old talk (Nice looking tyre)

or

BFG 255x85x16 KM2's, 33inch.

I like the idea of taller tyres as it will offer better traction and fix the speedo error but will it
· reduce fuel economy, as it is harder to push the taller tyres.
· reduce drivability / power delivery.
The MT's are a little wider but standard height. I think 285 x 75 x 16 would be just too big, too tall.

And beware of the standard drive line components with such tall tyres.....

[cal415]

285s are actually smaller diameter then 255s, 33.3 vs 33.7 if i remember correctly, just a wider tread face, i have compared the 2 side by side, i have 255s in maxxis bighorns as well as 285s in Mickey Thompsons at home already(I have way to many tyres ask my wife...) the 285 is definetly heavier though i havnt tried to weigh them, both are on dynamic 16x8's but wider offset on the 285s as they are for my county with large flares. the 255s are definetly taller and are worn more then the 285s, the Mickey T's seem larger then most other 285s i have compared them too as well(BFGs AT's MTs and KM2s, Maxxis bighorns, and some others)

Drover, What do you get out of a tank now you have upgraded the I/C, chip and decat? and what did it get prior to this?

[Drover]

Drover, What do you get out of a tank now you have upgraded the I/C, chip and decat? and what did it get prior to this?

Hey Cal,

Fuel economy has improved noticeable since the up grades.

Sitting on/over 110k's prior to up grades was about 11Lp/100k's now it is down to very low 10lp/100k's.

I have a 140lt tank and don't fill it up unless I am going on trip so my figures are estimates, but I am in no doubt that fuel figures have considerable improved.

Good info on the tyre sizes, thanks.

[cal415]

140L tank would be nice, is that a Long ranger tank with small side tank? i cant beleive they only put a 75L in a 130, it seems crazy, even the disco has a bigger tank.

[sav07]

Cal, I am running 285/75'sR16 Wranglers and getting about 11.5L/100 with a BAS remap on an 08 110 Puma.

[Allan]

I am just about to up grade tyres. Can't decide between -

265x75x16 MT BAJA MTZ's, 32inch in the old talk (Nice looking tyre)

or

BFG 255x85x16 KM2's, 33inch.

I like the idea of taller tyres as it will offer better traction and fix the speedo error but will it
· reduce fuel economy, as it is harder to push the taller tyres.
· reduce drivability / power delivery.
The MT's are a little wider but standard height. I think 285 x 75 x 16 would be just too big, too tall.

And beware of the standard drive line components with such tall tyres.....

Just put KM2 255/85 16's on mine. Drives very well, a bit off tyre noise but I can live with that, speedo now spot on and fills the holes very nicely and only required small adjustment to the lock stops Will check fuel consumption next tank full and report.

Allan

Allan

[Drover]

140L tank would be nice, is that a Long ranger tank with small side tank? i cant beleive they only put a 75L in a 130, it seems crazy, even the disco has a bigger tank.

Hey cal,

It is a Long range Automotive (LRA) tank, out of melbourne.

long range auxiliary & replacement fuel & water tanks for 4WDs | Designed & manufactured in Australia by LONGRANGE AUTOMOTIVE since 1989 (http://www.longrangeautomotive.com.au/)

All one piece, fits with sway bar and factory tow bar. Very neat fit. :D

[Wortho]

The width is what would make the difference with those sizes Mick, a 255 will drive much nicer. You've got them there try them both and see.
You still gotta bring it in for me to have a look at.

[Naks]

The bigger tyres leads to increased consumption is a myth.

Remember, when you change the tyre size, your odometer reading also goes off. So now you are calculating consumption based on an inaccurate reading of the mileage ;)

[Lorryman100]

The fuel usage on my Puma with an Alive remap is the same no matter what set of tyres I put on. Today I am running Mickey Thomson 305/70x16 Baja ATZ on alloys with a built in 30mm offset. In the summer I use the standard boosts with 235/85x16 and for mud plugging I use 265/75x16 BFG MT on modulars. The speedo is also accurate with the 305's compared to the 235's which put it out by a couple of mph on the slow side. I have found that the wider the tyre the better the ride even in deep snow where normally a thinner tyre would be best as it cuts through and offers less resistance. Here is a link to a tyre calculator which gives a good visual indication to different tyre sizes:

Tire size calculator (http://www.miata.net/garage/tirecalc.html)

[Nera Donna]

The fuel usage on my Puma with an Alive remap is the same no matter what set of tyres I put on. Today I am running Mickey Thomson 305/70x16 Baja ATZ on alloys with a built in 30mm offset. In the summer I use the standard boosts with 235/85x16 and for mud plugging I use 265/75x16 BFG MT on modulars. The speedo is also accurate with the 305's compared to the 235's which put it out by a couple of mph on the slow side. I have found that the wider the tyre the better the ride even in deep snow where normally a thinner tyre would be best as it cuts through and offers less resistance. Here is a link to a tyre calculator which gives a good visual indication to different tyre sizes:

Tire size calculator (http://www.miata.net/garage/tirecalc.html)


Excellent little tyre calculator Lorryman. Thanks for that. I’ve been using an old and tattered tyre spec leaflet I’ve had for around 20 years. This one is a really little rip snorter. ;)
Cheers

[cal415]

well just filled up tonight, worst tank yet, 600km on the dot with 68l fill.

I will be putting the tyres on sometime this week, running the 255s i guess i will see how it goes.

[PAT303]

600,whats wrong with mine then. Pat

[cal415]

driving style maybe? heavy right foot? i guess i have given it a bit more right foot this tank, driving has been a mix of city driving and drive to work in stop start traffic but in 80-90k zones all the way.

[cal415]

well for the 285's vs 255s vs 7.50x16s, so far i am noticing little difference, last 2 tanks first one on 255s i got 540km before the light came on filled up shortly after at 62L then next time on 285s 570km before the light came on filled up at just under 600km with 63L, all very similar driving, city and highway combined.

[cal415]

worst tank yet, no real highway driving this time, few runs on 80-90kph areas and about 4 hours of beach driving, light came on at 525km, this is on 285s still. Overall i found this to be a good sign considering the beach driving involved and some driving heavily loaded up with stuff in the tray.

[PAT303]

Mine got 505 when the light came on,I do give it the beans though. Pat

[cal415]

Which tyres Pat? i give mine a pretty hard time, i was happy with the last tank considering the beach driving, though i figured i would get a pretty constant 6-650 out of a tank, i guess maybe after a retune and EGR disable it might improve.

oh and looking back at the figures stated, these are real figures from the ODO, not adjusted to take tyres in to account, so inface i am probobly getting the same or better KM per L as i was with the 7.50x16s

[Allan]

I am at the moment attempting to get the worst urban consumption from mine with 255's. I am only doing around 10 km per day 5th gear rarely so will be interesting. Showing 150 km on the first quater tank but we will see. I'll fill it next week and see.

Allan

[PAT303]

Which tyres Pat? i give mine a pretty hard time, i was happy with the last tank considering the beach driving, though i figured i would get a pretty constant 6-650 out of a tank, i guess maybe after a retune and EGR disable it might improve.

oh and looking back at the figures stated, these are real figures from the ODO, not adjusted to take tyres in to account, so inface i am probobly getting the same or better KM per L as i was with the 7.50x16s

235/85.I don't believe in the drive easy last longer stuff,warm her up and get going and keep the combustion temps up. Pat

[cal415]

I am at the moment attempting to get the worst urban consumption from mine with 255's. I am only doing around 10 km per day 5th gear rarely so will be interesting. Showing 150 km on the first quater tank but we will see. I'll fill it next week and see.

Allan
With mine it seems the first 2/3 on the gauge goes fast and the last bit lasts for a few hundred KM

[Allan]

With mine it seems the first 2/3 on the gauge goes fast and the last bit lasts for a few hundred KM

Mine is the reverse on both vehicles, I can do 100km and the guage not move, then its away after half gonewithin a 100km or so find a B.P. You dont have long to go befoe Bing:(:(

Allan

[cal415]

Yes i get 100-150 before the needle moves too, then it drops till about a 1/3 of a tank within 200km then the last 200-250 from the last 1/3.

[grover7488]

mine doesn't really seem to change whether i run the 235 GG stocks or the 255 Km2's - normally about 600km for 62l

I put this down to the defa being as aerodyanic as a fridge so tyres are the least of the problem

when i tow the Jayco (sitting on 100km/h) i get about 12.5l/100km

i think that the tread pattern and type can make a difference. A soft muddie will prob have more friction than a AT or hwy tyre but still depends on the diameter % increase.

255 or 285 are not that big a difference from stock on a defa. if you go up a lot in diameter you will see differences.