Steel wheels, 17 vs 18 inch?

[DaveB]

The taller sidewalls can "flop" more as the vehicle take a curve. Reducing pressure with a 17" wheel should give you a wider footprint, and thus better flotation on the sand. That's the choices I need to figure out

Deflating the tyres gives you a longer footprint not a wider one.
Last thing you want in sand is a wider footprint as it then has to push against more sand to go forward.

View: https://www.youtube.com/watch?v=uN0Tf2eYPE8

View: https://www.youtube.com/watch?v=xyc8HYzEZPE&list=PLG5Om1_yP8jmdmF-fDCkHisnLICYf-ibJ&index=7

 

[rovingoz]

17 steel for me. Alloys just don't instill confidence on the Madigan Line.
18s are harder to source in remote areas (AU) & country towns. The mines here all run 16 & 17s so plentiful. Higher sidewall on the 17s gives you more to play with on sand and less risk on gibber roads & rougher tracks. Clearance wise, 18s only gain about a ¼ inch, better to up tyre size on 17s, and more on offer.

 

[Tazzieman]

As far as the question goes, I doubt anyone would notice the difference on road at legal speeds.
So 18" "handles better" sounds like parroted nonsense from the world of SUVs and sports cars.
And the Trialmaster is on light truck tyres with stiff side walls.
17" + LT tyres for an offroad focus, plus as has been stated, flexibility if you need a spare.
City drivers and those in small countries can have, and will have , what they like the look of.

 

[Steve.B]

Deflating the tyres gives you a longer footprint not a wider one.
Last thing you want in sand is a wider footprint as it then has to push against more sand to go forward.

View: https://www.youtube.com/watch?v=uN0Tf2eYPE8

View: https://www.youtube.com/watch?v=xyc8HYzEZPE&list=PLG5Om1_yP8jmdmF-fDCkHisnLICYf-ibJ&indei have

I have done a fair bit of sand driving over the last 44 years of owning 4x4s, and in my experience the taller and wider the tyre the better it is on sand.
A 33" tyre is significantly better than a 31" tyre but a 285/ 33" tyre is also significantly better on sand than a 235/ 33" tyre.
The taller and wider the tyre the better it is on sand, but also if you use the narrowest rim you can for the tyre size the tyre bags out better, a significant advantage on sand also, ( and less rim damage when traversing rocks and the like ), so if you have say a 285/70r17 on a 8" wide rim it will be better on sand than a 9" wide rim, but the 285/70r17 on the 9" wide rim will have better on the road handling less sidewall distortion a bit like the taller rims in the video.
If you were in a convoy of 4x4s on sand with identical wheel tracks, identical tyre widths, and a near supernatural driving ability to exactly follow the convoy leaders wheel tracks then the narrow tyres might be of use if the convoy leader has narrow tyres.
Narrow tyres are better on surface mud with a hard base and for fuel economy, everything is a compromise.

 

[AnD3rew]

I have done a fair bit of sand driving over the last 44 years of owning 4x4s, and in my experience the taller and wider the tyre the better it is on sand.
A 33" tyre is significantly better than a 31" tyre but a 285/ 33" tyre is also significantly better on sand than a 235/ 33" tyre.
The taller and wider the tyre the better it is on sand, but also if you use the narrowest rim you can for the tyre size the tyre bags out better, a significant advantage on sand also, ( and less rim damage when traversing rocks and the like ), so if you have say a 285/70r17 on a 8" wide rim it will be better on sand than a 9" wide rim, but the 285/70r17 on the 9" wide rim will have better on the road handling less sidewall distortion a bit like the taller rims in the video.
If you were in a convoy of 4x4s on sand with identical wheel tracks, identical tyre widths, and a near supernatural driving ability to exactly follow the convoy leaders wheel tracks then the narrow tyres might be of use if the convoy leader has narrow tyres.
Narrow tyres are better on surface mud with a hard base and for fuel economy, everything is a compromise.

Both my last two 4x4s have had 265/60/r18 I have done heaps of sand driving in both of them over the past 15 years, both beach and desert. Never been bogged in sand in either of them both great on sand.

 

[Steve.B]

Both my last two 4x4s have had 265/60/r18 I have done heaps of sand driving in both of them over the past 15 years, both beach and desert. Never been bogged in sand in either of them both great on sand.

It is good that the 31" tall 265/60r18 tyres work well for you, the old 7.50/16 were 31.7" tall, also worked ok on sand but the vehicles were a fair bit lighter in those days.
The 235/85r16 the modern replacement for 7.50/16 are also 31.7" tall but 2" wider, 9.5" for the 235/85r16 vs 7.5" for the 7.50/16. the 235/85r16 works better on sand but some of that difference would be the more modern design, A tubeless radial vs a stiff side walled tubed cross ply tyre.

 

[Barney]

There are always talks about the desert suitability. I've heard of a sand formula that can be used to determine suitability for slopes, dunes or even competitions. The simple logic of the formula: vehicles sink in the sand less easily the larger the wheel diameter, the higher the engine output, the width of the tires and the lower the weight of the vehicle. We all know that. The components result in a formula that I have found, the sand formula, i.e. suitability for use on sand. S = nt x d (square) x b x (P:B (square)) nt= number of driven wheels. d= wheel diameter in meters. b= tire width in meters. P= motor power in kilowatts. G= vehicle weight in tons. Now it can be seen whether the vehicle is only suitable for slopes 1-10. Or also suitable for dunes 10-30. Or competitively over 30. I'd be interested to see where the Grenadier compares. Does anyone know the tire width and the wheel diameter of the 17” AT? Maybe this topic has already been discussed, sorry for that.

 

[Tazzieman]

There are always talks about the desert suitability. I've heard of a sand formula that can be used to determine suitability for slopes, dunes or even competitions. The simple logic of the formula: vehicles sink in the sand

There is fine sand and coarse sand and sand like mud and sand that is quicksand. And people tow trailers and caravans.
There is no easy solution except to get stuck and do better next time!

 

[DenisM]

There are always talks about the desert suitability. I've heard of a sand formula that can be used to determine suitability for slopes, dunes or even competitions. The simple logic of the formula: vehicles sink in the sand less easily the larger the wheel diameter, the higher the engine output, the width of the tires and the lower the weight of the vehicle. We all know that. The components result in a formula that I have found, the sand formula, i.e. suitability for use on sand. S = nt x d (square) x b x (P:B (square)) nt= number of driven wheels. d= wheel diameter in meters. b= tire width in meters. P= motor power in kilowatts. G= vehicle weight in tons. Now it can be seen whether the vehicle is only suitable for slopes 1-10. Or also suitable for dunes 10-30. Or competitively over 30. I'd be interested to see where the Grenadier compares. Does anyone know the tire width and the wheel diameter of the 17” AT? Maybe this topic has already been discussed, sorry for that.

The 17"wheels run 265/70/17 tyres Bridgestone and BFG K02 same nominal size
Diam: 0.803m
Width: 0.265m
Circumference: 2.520m

 

[Barney]

Thank you. That means 4 x (0.803x0.803m) x 0.265 m x ((183 kW diesel : (2.7t x2.7t)) = 17.16
Means it is ok in the dunes. Too much weight.

 

[DenisM]

Thank you. That means 4 x (0.803x0.803m) x 0.265 m x ((183 kW diesel : (2.7t x2.7t)) = 17.16
Means it is ok in the dunes. Too much weight.

As @Tazzieman pointed out however, the nature of sand varies enormously... be it wet/dry/hot/cold/particle size/compaction.... I guess I'll find out in due course!

 

[globalgregors]

There are always talks about the desert suitability. I've heard of a sand formula that can be used to determine suitability for slopes, dunes or even competitions. The simple logic of the formula: vehicles sink in the sand less easily the larger the wheel diameter, the higher the engine output, the width of the tires and the lower the weight of the vehicle. We all know that. The components result in a formula that I have found, the sand formula, i.e. suitability for use on sand. S = nt x d (square) x b x (P:B (square)) nt= number of driven wheels. d= wheel diameter in meters. b= tire width in meters. P= motor power in kilowatts. G= vehicle weight in tons. Now it can be seen whether the vehicle is only suitable for slopes 1-10. Or also suitable for dunes 10-30. Or competitively over 30. I'd be interested to see where the Grenadier compares. Does anyone know the tire width and the wheel diameter of the 17” AT? Maybe this topic has already been discussed, sorry for that.

I like it, not heard of that. I’ve a bit of a desert obsession and have tackled several (12+).
As mentioned above, they vary drastically in form and character, as Aussies know just from ours.

Do we know where this heuristic comes from? Is it based on Moroccan (Western) Sahara experience?

 

[Barney]

I like it, not heard of that. I’ve a bit of a desert obsession and have tackled several (12+).
As mentioned above, they vary drastically in form and character, as Aussies know just from ours.

Do we know where this heuristic comes from? Is it based on Moroccan (Western) Sahara experience?

I don’t know were it’s from. Saw in in a book about Offroad. I believe you there’s a lot off differenz between sand and sand.

 

[Phillips]

The max pressure and load rating of the 17” bfg is 3195 lbs at 80 psig while the 18” bfg is 2835 lbs at 65 psig. I believe the 17” version of this tire has additional plys in it’s construction. This info is from tire photos at the Colorado event last week.

 

[Barney]

There is fine sand and coarse sand and sand like mud and sand that is quicksand. And people tow trailers and caravans.
There is no easy solution except to get stuck and do better next time!

Do you heard about Fech Fech. This must be very fine powder �

 

[frankkk]

The Sahara alone has about 15 different types of sand. They can be inspected at the Sahara Museum in Ghardaia in Algeria. A friend, his family owns a commercial sandpit, has got about 50 sands in his collection.

The theory is well and good, as pointed out, the practise is different though.

Citroen undertook several expeditions 100 years ago with "Autochenilles" into the deserts of the world in Africa and Asia. Earlier attempts by Renault in Algeria with 6-wheelers had partially failed, mainly due to tire constraints..they just couldn't carry enough spares..

La croisière jaune : l'expédition Citroën de légende - URALISTAN

URALISTAN - croisière jaune, mission Centre-Asie ou 3e mission G.M. Haardt Audouin-Dubreuil. L'expédition en autochenille Citroën de Beyrouth à Pékin, 1932.

uralistan.fr

The Renault story, both in French only..:-((

Renault en Afrique

Tires are a source of endless discussion amongst 4x4 enthusiasts..always have been and always will be. Different strokes for different folks, I guess.

Underlying principle when into serious off-roading: Tires are your best friend, buy the very best you can afford and look after them. Tire pressure (mainly lack of) is the source for 90% of all punctures on one hand and is the biggest source (or lack) of traction, on the other.

Tubed tires are a thing of the past. A tube can always be inserted if need be, a shorn off valve on a tube can't be replaced though. Sometimes you hear "tire specialists" saying "tubed tires for the desert"...don´t listen, that´s a load of nonsense. Tubeless tires with triple sidewalls is what you want. The more rubber, the better, i.e. 16" is preferable over 17" is preferable to 18" with the same overall circumference.

"Standard" tire for desert applications in Africa on EU vehicles used to be a 255/85 16 BFG MT or 8.25/9.00 R 16 XZL..with the latter being rare and sort of unaffordable. 17"are a very recent thing in Africa, 18" unknown and 16" widely available.

The earlier comment in a post on narrow rims is a valuable one. A tire dealer will give you a no, no on 6" rims for 255, that is his theoretical approach. In practise, the narrower, the better on sand (we have run them on 5,5" down to 0,8bar w/o any problems)..

More rigid "truck type" tires are unsuitable on sand, due to their inability to flex in the sidewalls. They are built for strength with heavy loads on pickups or the like, mainly on road, even if the name suggests different:

285 70 17 126 Car Tires | BFGoodrich Tires USA

Shop for 285/70R17 Car Tires in Shop by Size. Find tires for your Car with a 17-inch diameter, 70 aspect ratio, and 285 widths.

www.bfgoodrichtires.com

 

[DaveB]

There are always talks about the desert suitability. I've heard of a sand formula that can be used to determine suitability for slopes, dunes or even competitions. The simple logic of the formula: vehicles sink in the sand less easily the larger the wheel diameter, the higher the engine output, the width of the tires and the lower the weight of the vehicle. We all know that. The components result in a formula that I have found, the sand formula, i.e. suitability for use on sand. S = nt x d (square) x b x (P:B (square)) nt= number of driven wheels. d= wheel diameter in meters. b= tire width in meters. P= motor power in kilowatts. G= vehicle weight in tons. Now it can be seen whether the vehicle is only suitable for slopes 1-10. Or also suitable for dunes 10-30. Or competitively over 30. I'd be interested to see where the Grenadier compares. Does anyone know the tire width and the wheel diameter of the 17” AT? Maybe this topic has already been discussed, sorry for that.

This is great but is there also a formula for malls & coffee meets?
I would hate to spend all this money and then find out I have purchased the wrong vehicle.

 

[Barney]

The Sahara alone has about 15 different types of sand. They can be inspected at the Sahara Museum in Ghardaia in Algeria. A friend, his family owns a commercial sandpit, has got about 50 sands in his collection.

The theory is well and good, as pointed out, the practise is different though.

Citroen undertook several expeditions 100 years ago with "Autochenilles" into the deserts of the world in Africa and Asia. Earlier attempts by Renault in Algeria with 6-wheelers had partially failed, mainly due to tire constraints..they just couldn't carry enough spares..

La croisière jaune : l'expédition Citroën de légende - URALISTAN

URALISTAN - croisière jaune, mission Centre-Asie ou 3e mission G.M. Haardt Audouin-Dubreuil. L'expédition en autochenille Citroën de Beyrouth à Pékin, 1932.

uralistan.fr

The Renault story, both in French only..:-((

Renault en Afrique

Tires are a source of endless discussion amongst 4x4 enthusiasts..always have been and always will be. Different strokes for different folks, I guess.

Underlying principle when into serious off-roading: Tires are your best friend, buy the very best you can afford and look after them. Tire pressure (mainly lack of) is the source for 90% of all punctures on one hand and is the biggest source (or lack) of traction, on the other.

Tubed tires are a thing of the past. A tube can always be inserted if need be, a shorn off valve on a tube can't be replaced though. Sometimes you hear "tire specialists" saying "tubed tires for the desert"...don´t listen, that´s a load of nonsense. Tubeless tires with triple sidewalls is what you want. The more rubber, the better, i.e. 16" is preferable over 17" is preferable to 18" with the same overall circumference.

"Standard" tire for desert applications in Africa on EU vehicles used to be a 255/85 16 BFG MT or 8.25/9.00 R 16 XZL..with the latter being rare and sort of unaffordable. 17"are a very recent thing in Africa, 18" unknown and 16" widely available.

The earlier comment in a post on narrow rims is a valuable one. A tire dealer will give you a no, no on 6" rims for 255, that is his theoretical approach. In practise, the narrower, the better on sand (we have run them on 5,5" down to 0,8bar w/o any problems)..

More rigid "truck type" tires are unsuitable on sand, due to their inability to flex in the sidewalls. They are built for strength with heavy loads on pickups or the like, mainly on road, even if the name suggests different:

285 70 17 126 Car Tires | BFGoodrich Tires USA

Shop for 285/70R17 Car Tires in Shop by Size. Find tires for your Car with a 17-inch diameter, 70 aspect ratio, and 285 widths.

www.bfgoodrichtires.com

Thx Frankkk,
yes, you can definitely discuss tires just as emotionally as hunters can about the right hunting ammunition. Caliber, lead or unleaded, deformations or partial fragmentation..... and so on

 

[Wayneos]

This is great but is there also a formula for malls & coffee meets?
I would hate to spend all this money and then find out I have purchased the wrong vehicle.

Take the width of your tyre and it's profile, say 70% of 265mm. This gives you the length of your cannoli. Check your dipstick and match the colour of the oil to the coffee. If these things don't line up, find a better cafe.

 

[Defender2023]

255/70r18 or 265/70r17 should be the quite the same for offroading