Mud-club

Vehicle & Technical => Defender => Topic started by: Jim-Willy on June 10, 2008, 22:31:36

Title: Tyres and MPG......
Post by: Jim-Willy on June 10, 2008, 22:31:36
I run 235/85 M/T's on the 90 which is my daily driver, she is doing about 200 miles to a tank which at current prices is killing me.  I was thinking try a less aggressive tyre but, anybody any experience of whether this will improve things enough to bother?  Should i go for a narrower or wider tyre at the same time?  Don't know whether a gay fat tyre will float the landy better allowing the wheel to turn easier or whether the decreased weight of a skinny tyre would be better and create less resistance?

BTW there is no way on this earth i am running 205 road tyres i would sooner buy a car but there must be some middle ground?!

Any other mpg improvements i could make?

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Title: Re: Tyres and MPG......
Post by: DogVanMan on June 10, 2008, 23:11:23
A Yorkshire man looking to save a bit o brass..? Never!

From one (exiled) Tyke to another, here's a couple of thoughts for u..

Generally speaking the wider the tyre, the more rolling resistance and the worse the MPG
Taller the tyre, higher gearing = possibly better MPG
Within limits, the more air pressure, the less rolling resistance, the better the MPG (I.e. Just make sure they're not under-inflated, don't go over inflating them)

235/85/16 are pretty tall as standard(ish) sizes go and not too wide. I'd be inclined to  stick to the same size, go for a second set of wheels tyres in either A/T or road pattern. Since you've got a set of M/T's why not keep them and run the old girl on road tyres if you really want to save a bit of cash. Then again, if you're not carfeful, you'll spend so much on them that you'll never recoup it.

My top tight Yorkshireman's tip is scour ebay for a cheap set of 235/85/16 road tyres that someone is offloading from their standard Land Rover fitment alloys for sexier tyres. I bought a set of 4 half worn General Grabbers last year for £15!

Or.. God forbid.. tha' could drive slower.

P.S. I just worked out that 200 miles from a 90 tank is about 18-19 to the gallon? About 50 litres a fill? (At least that's what my P reg 90 300Tdi takes).. That's more than just tyres mate.. I'd have thought you'd be seeing 25ish even on m/t's. I used to get 26-28 on A/T's in your size.

G
Title: Re: Tyres and MPG......
Post by: ChrisV8 on June 11, 2008, 10:23:56
 :roll:well from a tight Cumbrian resident, I agree , you need less aggressive tyres for road use, my 110 runs a Jappy diesel, but with good old Colway MTs 235/85 x 16 mpg was about 23-25, but previously using General ATs it was around 35mpg. With the present fit Durango Ats I get around 35mpg, I even got 25 mpg towing the latest 90 Project back from Scarborough on my Ifor Williams, well impressed.

Muds cause a lot of drag in my view I also have a full roof rack on as well. The Isuzu engine was always better than a tdi, but my farmer mate (the well known short pocket profession) runs his 300 tdi 90 on a set of Grabber Ats as factory fitted for long distance holidays etc, bought with no wear from a poor misguided soul who wanted something "more meaty looking" for £100.00 a set of 5 !! He gets 33 - 35mpg on those, he swaps back to his beloved set of General Ats for the farm use and gets very similar mpg.

Definitely worth changing I think, I would also concur that looking around can turn up some bargains with less impressive tread patterns !
Title: Re: Tyres and MPG......
Post by: Jim-Willy on June 11, 2008, 17:02:03
Cheers dudes....  The mpg is low due to the amount of queuing i do i think, i will keep my eye out for some road tyres.
Title: Re: Tyres and MPG......
Post by: extreme90 on June 11, 2008, 17:57:47
just to throw a spanner in the works
my comp truck is better on fuel than my box std 90
and its on 35inch simex running stock 90 trans ratio's, just got the engine stupidly tweaked

i couldnt belive the difference in fuel economy on the std 90 when i mildy tweaked that

both are 200's btw
dan
Title: Re: Tyres and MPG......
Post by: tom38 on June 11, 2008, 19:30:22
im running 255 65 16 mt's on my 200 tdi used daily n getting around 27 ish to gallon with a roof rack on if thats any help :?
Title: Re: Tyres and MPG......
Post by: spoofer2888 on June 11, 2008, 21:53:20
i used to run 750/16 MTs on mine now ive changed to 750/16 ATs and ive not noticed and difference in the MPG  :?
Title: Re: Tyres and MPG......
Post by: Tommo on June 12, 2008, 17:12:44
get some michelin XZL's or whatever the mod use. you used to be able to get a wheel and tyre from withams for £20. they are 750-16s, narrow as awt but look alright, and [!Expletive Deleted!] all rolling resistance. And they will still go off road. (if like me you cant be bothered changing wheels everytime you want to go off road, whats the sodding point? may as well take front prop off while im at it, oh and take the lift kit off......  :evil:)
Title: Re: Tyres and MPG......
Post by: jimthelandyman on June 12, 2008, 17:38:32
I am not complaining i'm getting about 25 mpg running on 35's bfg muds
Title: Re: Tyres and MPG......
Post by: Tommo on June 12, 2008, 17:41:32
I am not complaining i'm getting about 25 mpg running on 35's bfg muds

dont worry, jim makes the rest up in drivetrain components!
Title: Re: Tyres and MPG......
Post by: clairedave on June 12, 2008, 18:22:20
im getting  28 -30 mpg on 235 85 16  on general grabbers , plus changing transfer box to 1.222 for motorway work hope to get even more :D
Title: Re: Tyres and MPG......
Post by: DogVanMan on June 12, 2008, 20:45:00
get some michelin XZL's or whatever the mod use. you used to be able to get a wheel and tyre from withams for £20. they are 750-16s, narrow as awt but look alright, and [!Expletive Deleted!] all rolling resistance. And they will still go off road. (if like me you cant be bothered changing wheels everytime you want to go off road, whats the sodding point? may as well take front prop off while im at it, oh and take the lift kit off......  :evil:)

Aye.. they go off road every time you go round a corner a bit quick, like! lol

G ;-)
Title: Re: Tyres and MPG......
Post by: Jim-Willy on June 12, 2008, 21:23:15
Got some old receipts our and it is doing around 23mpg......  I think i have a engine problem but i still think i'm going to try less aggressive tyres aswell.
Title: Re: Tyres and MPG......
Post by: pux on June 12, 2008, 21:57:36
Got some old receipts our and it is doing around 23mpg......  I think i have a engine problem but i still think i'm going to try less aggressive tyres aswell.
Jim is your landy an auto?? as that will do less MPG than a normal manual Landy :D
Title: Re: Tyres and MPG......
Post by: Jim-Willy on June 12, 2008, 22:10:28
Not that much less tho', its only a 90" like so she is pulling no weight and i drive her steady on the motorways (which is where the bulk of the mileage is done these days).
Title: Re: Tyres and MPG......
Post by: Rich_P on June 13, 2008, 12:33:59
Even so, a potential difference of 5mpg is very real between manual and auto boxes in these motors.
Title: Re: Tyres and MPG......
Post by: Saffy on June 13, 2008, 21:06:30
Even so, a potential difference of 5mpg is very real between manual and auto boxes in these motors.

get back to the leafer section you ! :lol:

As for the topic, I have no idea what my MPG is but I do know that on Avon Rangemaster 7.50's on standard rims the truck has a higher top speed, *gives the impression* of accelerating faster and is more responsive through out the gears than when compared to when running on the Mud's (anaconda's on 8 spokes rims). This surely translates to better MPG.
Title: Re: Tyres and MPG......
Post by: Jim-Willy on June 15, 2008, 14:18:23
Well i have purchased some gay a/t's so we will see whether there is any improvement.
Title: Re: Tyres and MPG......
Post by: Jim-Willy on June 22, 2008, 20:07:43
Well it looks Gay but we will see if i see any improvement.......

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