Basic Tire Information

[llesra]

Before you go and post something, see if this answers your question. Going with a larger tire means you'll go slower and use more gas. Increasing tire size also changes the gear ratio and adds stress to the drivetrain.


Discovery I 94-99


<29"

205/80/16: Stock size in other countries. same height as 235/70-16.

235/70/16: Stock tire size.

255/65/16: same height as stock but wider

225/75/16: same height as stock but narrower

245/70/16: a little taller and wider than the stock size


30"-31"

255/70/16: slightly taller and wider than stock, but still fits with no lift.

245/75/16: fits on stock height but popular size for 2" lifts. some trimming on the rear wheel well and adjustment on the steering stops.

215/85/16: same height as 245/75/16 but narrower.

265/70/16: about as tall as 245/75/16 but wider.


32"

265/75/16: Same as stock Defender tires. Will require some more trimming. lift highly recommended.

235/85/16: same height as 265/75/16 but narrower.


33"

255/85/16: about 33". a lot more trimming required and you should consider upgrading to hd axles.

285/75/16: also about 33" but wider. a lot more trimming required and you should consider upgrading to hd axles. offset whdeels recommended.



Discovery Series II 99-04


<29"

255/65/16: Stock tire size.

255/55/18: optional stock size.


30"-31"

255/55/19: stock size for range rover III. works fine for DII

255/70/16: a little taller than stock.

245/75/16: a little taller than stock. tire manufacturers recommended these be fitted with 7" wheels, but 8" works fine.


32"

275/70/16: possible to fit without lift. minor rubbing.

265/75/16: possible to fit without lift. minor rubbing.

285/60/18: 32" tire for the 18" rim. costs much more than 16".


33"

285/75/16: even taller than 265/75-16, requires around 3" of lift. Very wide and requires trimming. consider upgrading to hd axles & getting lower gears.

255/85/16: a bit taller than 285/75-15 but narrower. consider upgrading to hd axles & getting lower gears.



Defender


32"

265/75/16: stock size tire

235/85/16: same size as stock but narrower


33"

255/85/16:

285/75/16:

33x12.5:


>34"

305/75/16:

35x12.5:



Range Rover 4.0/4.6 96-02


<29"

Stock tire diameter.

255/65/16

255/55/18


30"-31"*

Works well with EAS but rubs a little on access mode.

Fills tire wells nicely.

255/55/19 (RRIII wheels & tires)

255/70/16

245/75/16

265/70/16


32"*

Fine on high mode, but will rub on the lower settings.

May not be able to turn on access height.

Highly recommended that you convert the EAS to lifted coil springs.

275/70/16

265/75/16

285/60/18

*any size bigger than stock will not fit in the spare tire holder in the floor.



Here's a great tire size calculator and comparison.

Calculator & Comparison

Rovertracks and Great Basin Rovers both sell HD axles for those wanting to or are running bigger tires.

Rovertracks
Great Basin Rovers

[disco12]

great post LLesra I'm going with 265/75/16 I have a OME 2/half inch so I guess that will be just fine for me.

[2BIG]

Arsell, that is about the best write-up I've seen on for a tire conversion chart as I"ve seen. Thanks for taking the time to do this.......Time to start sweet talking the wife

[300bhp/ton]

Originally Posted by llesra

Before you go and post something, see if this answers your question. Remember, increasing tire size changes the gear ratio and adds stress to the axles.


Discovery I 94-99

Nice post, although Discovery's came out in 1989 not 1994

[rmuller]

Originally Posted by 300bhp/ton

Nice post, although Discovery's came out in 1989 not 1994

94 was the first year in the US

[keptin]

Great post arsell, I wish we could make it a sticky. Do mods have that power now?

I've already got tires, but for the sake of someone I'm trying to help; What would be the best tire size for use in a stock disco II with regards to off-roading?

I'm thinking 255/70/16s. They will be a bit taller and have the same width as the stock tires. I personally think the DIIs would 'like' the slightly wider 255s over the 245s.

[300bhp/ton]

Originally Posted by keptin

I've already got tires, but for the sake of someone I'm trying to help; What would be the best tire size for use in a stock disco II with regards to off-roading?

I'm thinking 255/70/16s. They will be a bit taller and have the same width as the stock tires. I personally think the DIIs would 'like' the slightly wider 255s over the 245s.

While I don't disagree with you're suggestion it's very hard to recommend a single size as there are so many different requirements depending on use and intent.

Thus what is right for one person can be completely wrong for another.

[keptin]

hehe, I know, but if we create a simple scenario where the person will be doing light off-roading with a stock vehicle, but is looking for slightly larger and more agressive tires.

It's hard to say there is a 'best' tire size, but its not to difficult to say there is a 'best fit' (ie. average best) that most people would be happy with. There are reasons why the majority of off-roading DII owners don't have 245/70-16s....I'm trying to find out what is the commonly used size for this purpose w/ a stock lift and perhaps the reasons behind using that size of tire.

[bilbo42]

As a newbie, we need all the help we can get! Great site. Bil

[Crysyn]

I found this on another land rover site, thought it might be useful:


"Bigger Tires have something to do with my speed, mileage and oil?"

What you talkin' 'bout Willis?



got to thinking… which is scary in and of itself… but I thought I would share my thoughts anyway.

Speed. Or lack there of. Fuel efficiency. Or lack there of. Scheduled maintenance. Hmm…

Like many folks reading this, I’ve fitted larger tires on my truck. Like a lot of you, I run 265/75 16s. I’m sure you’ve noticed your speedometer is off. If you haven’t, it is.

Running three different GPSs over several semi-controlled experiments, I found my speedometer/odometer to be about 11% off. If I am going an indicated 65 mph on the speedo, in reality I am going just over 72 mph. No biggie, I just run around an indicated 60 mph which is equivalent to 67mph and forget about it. If my odometer says I have gone 100 miles, I have really gone 111 miles.

So what’s the big deal?

Let’s take a look at the components of the term “mph”. Miles Per Hour. If your mph is off 11% like mine, guess what’s really off… your miles.

An hour is an hour is an hour. It’s constant. It doesn’t change, but your miles do. If you are going 65 mph that means in 1 hour you will cover 65 miles. If your speedometer is off 11% like mine is, you really have covered over 72 miles in the same hour.

Now, think of the total time you have driven your truck. If you've been behind the wheel 1,000 hours... that is a constant.

For example: if you have 67,500 miles on your odometer and you have had larger tires on the truck over these 67,500 miles, that means in reality you have 11% more miles than the indicated 67,500; your truck really has nearly 75,000 miles on it!

And, how frequently do you change your oil? If you do it according to Land Rover, you change it every 7,500 miles. If you do it according to common sense, you more than likely change it every 3,750 miles (half of the 7,500). And some of you change it every 3,000 miles.

So let’s talk about a few things…

I already talked about speed. If your speedo is off by 11% like mine, here’s a chart of how fast you are really going…

Indicated on the Speedo

What you're really doing

25 mph - 28 mph

30 mph - 33 mph

35 mph - 39 mph

40 mph - 44 mph

45 mph - 50 mph

50 mph - 56 mph

55 mph - 61 mph

60 mph - 67 mph

65 mph - 72 mph

70 mph - 78 mph

75 mph - 83 mph

80 mph - 89 mph

Back to oil. How frequently do you change yours? If you said 7,500 miles per Land Rover’s recommendation, then taking into account the 11%, you’re really not changing the oil until it has been in your engine over 8,300 miles! If you go with the 3,750-mile interval, in actuality you are changing it at just over 4,150 miles. And you 3,000-mile folks are changing it after it has been in your engine for 3,333 miles. And beyond oil… think of all of the other maintenance items that are based on mileage…

Now, let’s say you wanted to buy a used rig. Let’s say you found one with 82,000 miles on it. That’s not too bad. Good price? You decide to buy it. If this truck has had larger tires on it it’s entire life, and if the speedo/odometer was off 11%, the 82,000 miles indicated on the odometer is really over 91,000 actual miles on the truck! Would you pay the same thing for a truck with 82,000 miles verses a truck with 91,000?

So, what are you saying?

Watch your speed. If you have larger tires, check your odometer against a GPS. Find out if it is off. If it is, calculate the difference by using the following method and calculation:

Reset your odometer and GPS to zero. Drive 10 miles (preferably in a straight line… interstate… on a clear day… so GPS isn’t affected). How many miles does your GPS say you went? Mine would say 11.1.



The difference I found is about 11% with 265/75 16 tires. Your truck may be different. It may be 9% off… it may be 13% off… it may not be off at all (but I bet it is though if you have larger tires).

Oil changes? If you truly want to change your oil at 3,750-mile intervals and your speedo/odometer is off by 11%, then you have to change it at 3,380-mile intervals using the odometer. And for those of you who let it slide to a 7,500-mile interval, you would change yours at a 6,760-mile interval if you used your odometer.

A silver lining?

On a positive note, say you fill up your tank with 25 gallons of fuel at an indicated 300 miles on the trip meter, doing a quick calculation, that's 12 mpg. But, that's also off by 11%... so in reality you're really getting 13.3 mpg! WOO HOO!!!

Another positive note is that you can sell your rig for more than it should be worth to someone who hasn't read this article...

I guess you could always get your speedo/odometer corrected and avoid all this...



As always, if you have any questions, feel free to ask!

-- Bill Mallin

[offroadLR3]

Too bad LR3 info isnt available.. =\

But great info for all the others!!

[sideview]

Originally Posted by offroadLR3

Too bad LR3 info isnt available.. =\

But great info for all the others!!

Here ya go NextStepDesigns Blog Archive LR3 wheel & tire specifications and options

[offroadLR3]

Thanks!!!

[Caz]

I need some advice!

Ive got a 1994 300tdi Disco + have recently bought some new wheels and tyres - 32". 11.50 x 15.

Ive got some box sections of steel which i'm going to put under the springs to lift it +2" (any advice on compressing the springs?). I also got new shocks, the rear shocks are +2" to account for the extra distance which they need to reach, but the ones for the front are standard in length because the 2" box section of steel at the front will go underneath both the spring and the shock.

I know that some cutting of the bodywork is necessary and have heard that tin snips are the best tool to use, but where to cut and how much to cut?

Is there anything else which i'll need to do to retain full articulation when off road?

Any further advice?