Pros & Cons of Tire Sizes

[bfeister]

Hey Everyone! So grateful for this forum, I recently got my 2005 LC and have already benefitted greatly from your help.

I'm looking for advice on tires & wheels. I assume that 18" or 20" wheels and tires are going to probably mean poorer gas mileage. Anyone have ideas as to how big the impact is?

Also, outside of that, at a real high level, what are the pros and cons of wider or more narrow tires? For example, is it always true that wider tires are better for off-roading (which I plan to do, I'm going to be right in the sweet spot near the "crossroads" out West)? Or are 16" (base) tires best for certain terrain types and 20" better for other terrain types when off-roading?

Any recommendations of the brands / models of wheels & tires you're using and have had a great experience with (including what kind of usage you're doing with them) would be most appreciated!

I won't be full-time off-roading the vehicle, so yeah, I can't completely tank my fuel efficiency since the truck will be my daily driver (but I only drive 20 miles every few days or so).

 

[BillZ260]

Heavier wheels and tires will net you less mileage than lighter ones, wheel size won't have much affect if the tire circumference is staying the same. All of that said, you won't change your mileage significantly one way or the other based on tires in this truck. Your mileage will suck no matter what. Get some all terrains, the same or one size up from whats on there now and have fun. You can upgrade as your understanding of the truck and your needs advance.

 

[lirritma]

I liked this site to do comparisons between tyre sizes - TireSize.com - Compare Tire Sizes, Specs, Prices & more . From my own research I'll list the following when you go for bigger size than your OEM tyre:

Pro's:
1. More surface contact which will help on off-road driving.
2. Potentially a softer ride on tar.
3. Slight lift.
4. Looks cool

Con's:
1. Your speedometer will be wrong. Your real speed will be faster than the what is shown. Not a biggy if your keep it in mind.
2. Higher fuel consumption.
3. You might need to "open up" wheel arches to accommodate the bigger tyres.
4. The bigger tyre might not fit in the standard spare slot under the vehicle.
5. Potential more road noise.
6. Bigger tyres cost more.

But it is not all about size because there are other aspects that come into play like quality of construction, stiffness of sidewalls and tyre pressure. In the end it comes down to a few trade-offs and there is no answer that is best - you go with what is best for your own driving needs.

My 100 VX is running on OEM's 275/70/16. I'm now going to 285/75/16 A/T of a brand with a strong sidewall. I do a lot of tar driving but enjoy the moments when I can get off-road and for that I need a tyre stronger than the normal A/T. I also like the look of the bigger tyre on the vehicle.

Enjoy the ride to get to what you want to do.

 

[MTKID]

You asked about the difference between 18" and 20" wheels. My personal experience is only with 16" & 17" on my LC but in general, the smaller diameter wheels allow more sidewall to flex off-road (more comfortable) and a larger contact patch to remain in contact with the ground for traction. These also allow you to drop tire pressure further without possible damage to the wheel. The larger diameter wheels would typically perform better on the road in high speed driving until you go too large and the road surface is too rough and you don't have the suspension to accommodate how rough the road is. Then it becomes a harsh ride that the vehicle bumps along struggling for traction. That said, none of us drive these like sports cars, so in general I feel the smaller wheel is a better fit, especially if you are planning on driving off-road.

You also asked about wide tires vs narrow tires. This depends on what you are driving on. In general I don't think you can say a wider tire always outperforms a narrow tire unless you are talking snow-wheeling where floatation is the key. In my area of varied terrain, I've always preferred a narrower tire that allows possibly the fitment of a taller tire before interfering with the vehicle. Unfortunately it will want to dig a little more through soft conditions rather than float, but that's a compromise I don't mind since I don't run just in the snow.

 

[bfeister]

unless you are talking snow-wheeling where floatation is the key. In my area of varied terrain, I've always preferred a narrower tire that allows possibly the fitment of a taller tire before interfering with the vehicle. Unfortunately it will want to dig a little more through soft conditions rather than float, but that's a compromise I don't mind since I don't run just in the snow.

Thanks so much, this really helps!

Yeah, that's the tough part. Actually, I want to off-road this thing, but the main purpose is to get me up a mountain top to the 10 acres I've bought on top of it. Snow is a serious concern, insofar as many people are skeptical about whether I can make it past these 5 very steep switchbacks that get me to the top of the mountain.

But that doesn't matter does it? I want to go narrow to cut THROUGH the snow and hit the rocks of my "driveway" underneath for max traction, right?

 

[Ohthetrees]

For tire rim size, generally smaller rim sizes are better for off road, allowing more tire sidewall to absorb blows from rocks, you can air down more without rim contacting rocks, and tires can flex and conform to obstacles better with smaller rims. I prefer 16” to any other size for my cruiser. When I air up my KO2s they have a stiff enough sidewall that I think on road performance is great too.

Some people think 18 inch is a perfect balance between pavement and offroad, but I’ll stick with 16 inch happily, and with nice AT tires I think it’s the best look too. Also the 16 inch rims are really very good, and you would be hard-pressed to find a lighter aftermarket rim.

I think most would agree that bigger than 18 inch is only appropriate for cruisers that stay on pavement. You won’t have enough side wall, and won’t be able to air down very much off road. On road you will get sharper handling, because less side wall to flex as you go around the corner, but at the cost of ride comfort. Everyone can make their own aesthetic choices, but I think big 20” plus wheels and low profile tires look ridiculous on the Land Cruiser or any other off-road capable vehicle.


As for tire width (not diameter, which was addressed above!), the current vogue is that wider is better for off-road, I think it depends on conditions. On soft sand the wider tire is clearly better. But in many cases a narrower tire would be better, for instance shallow mud or loose gravel on top of hard base is better with a narrow tire that has an easier time cutting through the mud down to the grippy surface below. Personally I think many people have tires that are too wide for best all-around performance.

If it were mine, I would keep the 16 inch wheels, plastidip them if you want an appearance upgrade, and put on 33 inch BFG KO2 tires 275/85 16. I’m really happy with the set up on and off road.

 

[uzj100]

What year 100? Lockers? A-Trac.

Tire and wheel size is important off road for the ability to air down. My 285/70 R 18s aired down to 15 psi work pretty well however switching back to 16s may in the future to get more sidewall flex.

AT vs MT is big trade off as well. I had Goodyear Duratracs and they are like a hybrid AT/MT and they were amazing in the snow. They were quiet at first however they got much louder with age. Not loud like the KM2's I have now but much louder than a standard worn AT tire.

 

[MTKID]

Thanks so much, this really helps!

Yeah, that's the tough part. Actually, I want to off-road this thing, but the main purpose is to get me up a mountain top to the 10 acres I've bought on top of it. Snow is a serious concern, insofar as many people are skeptical about whether I can make it past these 5 very steep switchbacks that get me to the top of the mountain.

But that doesn't matter does it? I want to go narrow to cut THROUGH the snow and hit the rocks of my "driveway" underneath for max traction, right?

That is correct, until the rocks of your driveway are under so much snow that the digging high-centers your truck on the snow. So it depends on the depth. In the circumstances where the snow is deep enough to cause problems you will want to play with lower tire pressure, even with skinny tires. It is amazing how much difference tire pressure makes in the snow. Just pick up an inexpensive 12v compressor you can use to air back up when you get back to pavement and make sure to keep a correct size spare tire in case you do drop a bead.

 

[RedHeadedStepChild]

There are 3 interrelated sizes that need to be considered here. You mention rim diameter and that has been covered a bit already. There is tire width and finally overall tire diameter as well. I'll touch on all three.

Rim diameter: from a functional standpoint, this needs to be considered in terms of its effect on sidewall and availability of tire options. It's already been said, but as with so much of what we do, you need to balance your on road requirements with your off-road desires. More sidewall = more flex at low pressures = better low speed traction (longer footprint and more mechanical keying on uneven surfaces). Less sidewall means less lateral deflection during faster manuevers= better handling. How meaningful this is on rigs like these is debatable, but I tend to agree with the above statement that 18" and below is ok,but at 20" you have decided the mall is your domain.
Aesthetically rim diameter is a personal choice that only you can decide.

Section width: wide tires have become a bit of a fashion, but unless you are doing a lot off beach/dessert dune driving, I see no point in going wide. We have already discussed the narrow tire's superior ability at digging in, but they also put less strain on steering hardware (If anyone doubts this try a head to head comparison in a rig without power steering), and potentially better mileage due to less rolling resistance- it's debatable whether you'll notice this tank to tank. At the end of the day, There is a reason why engineers, when not driven by marketing and sales, used to spec very narrow tires on 4x4s.
There are also acceleration/deceleration reasons why narrow is better. I'll get into that below.

Overall diameter: The primary functional thing you're buying here is ground clearance, though many people just like the look of a large diameter tire. Again, aesthetics are up to you. You get 1/2" of ground clearance for every extra 1" of diameter. Secondarily, a larger diameter tire has an easier time rolling over obstacles. Like all things in life, this comes with trade offs. The impact on the speedo has been mentioned, but the more important trade off is with acceleration and deceleration. With a larger diameter tire, the torque transmitted through the axle has a longer lever arm it must work on before creating linear motion (think of a cheater bar from the bolts point of view), therefore every part of the drivetrain must work harder to turn a larger diameter tire. Additionally, as you move rotational mass outward from the axis of rotation, you increase the moment of inertia-in layman terms, for two tires of identical weight, the larger diameter will be harder to accelerate/decelerate. Along these lines, with two tires of identical diameter, the wider tire has more mass at the outer extreme and will have a larger moment and therefor have the same drawbacks. The impact to the driveline also works in reverse. A larger moment of inertia will be harder to stop and so taxes your brakes more. The general consensus amongst the professional off-road trainers and tire engineers I've talked to is that about 33" is as large as you'd ever want to go (reliably)if you're not looking to do extensive driveline mods. It just so happens, if you go a little narrower, this is what you can fit on a LX470/100 without a lift or cutting fenders.

Hopes this helps.

 

[geanes]

In the end, I think 16" and 18" wheels are the min and max of the appropriate range. 16" is more biased to off-road IMHO, whereas 18" is a solid balance where the majority of your driving is on-road. 33" is the overall diameter most go with as it requires no lift and really is more than fine in nearly every case. I run 275/70/18 KO2 (33" overall) and find them more than sufficient for on-road AND off-road, dry, wet, sandy or a little snow. I run all over the passes of Colorado and the desert harshness of Big Bend and South Padre Island with 40psi on-road and down to 18psi off-road. Never had an issue with denting a rim or rolling a tire (knock on wood). I like the look of a 33" overall on an 18" wheel. I think the 16" look a little blimpy. Keep in mind, your odometer is going to be wrong.....the speedometer is off (5.1 mph at 70 indicated for me). That means I have to be very cognizant of fluid and maintenance intervals as they can be off a fair bit over time.

 

[bfeister]

What year 100? Lockers? A-Trac.

This is a 2005, so yeah, 100 series. It's 100% factory default right now, haven't added or modified anything just yet.

 

[bfeister]

until the rocks of your driveway are under so much snow that the digging high-centers your truck on the snow

This is really helpful! What kind of snow depth are we talking? This is a tough decision, insofar as I don't exactly how much to expect (will research that). But any thoughts on what the average snow accumulation "breakpoint" might be? For example:

"If your average accumulation is 6", you want narrower tires. If your average accumulation is 12" you want wider tires."

 

[RedHeadedStepChild]

This is really helpful! What kind of snow depth are we talking? This is a tough decision, insofar as I don't exactly how much to expect (will research that). But any thoughts on what the average snow accumulation "breakpoint" might be? For example:

"If your average accumulation is 6", you want narrower tires. If your average accumulation is 12" you want wider tires."

The limiter is when you're floating on the skid.
We regularly get 6-12" in NH. Not a big deal.

 

[trdcorolla]

I went down this path a few months ago, decided to split all the pro's and con's mentioned above and went 17" wheels with 32" tires. My reasoning is the 100 already felt slow compared to my V8 4runner and it'll be a little easier on the 4spd transmission/drivetrain when I accelerate. Or that's what I tell myself (when I sometimes feel like I should have went 33's).

 

[MTKID]

This is really helpful! What kind of snow depth are we talking? This is a tough decision, insofar as I don't exactly how much to expect (will research that). But any thoughts on what the average snow accumulation "breakpoint" might be? For example:

"If your average accumulation is 6", you want narrower tires. If your average accumulation is 12" you want wider tires."

Man, I hate to complicate this even further for you, but it’s not just the depth of the snow but also the condition of the snow. Is it wet and heavy or dry and fluffy? Has it warmed up a little since the last snowfall and then frozen again? I’ve driven in 36”+ of snow that allowed progress that made us feel invincible and I’ve driven in 12” of crusty snow with sugar underneath that made us feel like just going home.

Most of the recommendations above can show you that 33” is the most common and is likely a good fit for you to start with. The next thing to do is to determine the wheel you’ll be putting them on. Likely 18”, since that’s what you have, if I understand correctly. 16” OEM wheels should be easy to purchase if you want a second set of wheels & tires, 17” options are available from Tundra wheels like the Rock Warrior but more difficult to find at a reasonable price. So if you are landing on your 18” wheels, then start looking at different popular tires. BFG, Goodyear, Cooper, Toyo, etc. In general, the more open the tread design, the better it will perform off-road, but they will need sipes to get traction in the winter. But the more open tread designs will be noisier on the pavement. I feel it is important to have a good local tire shop to support whichever one you choose. And my perspective on a good middle of the road tire is likely different than other people’s. I’ve run BFG A/T’s in 295/75R16, Duratracs in 315/75R16 and now Pro-Comp A/T Sport in 37 12.5R17. I can recommend the BFG’s if you want slightly better road manors, and the Duratrac’s if you want a little better off-road performance. And there are a lot of other good tires you can consider.

Where are you moving to?

 

[RootMeanSqr]

Don't over think it. You will soon be in analysis paralysis, if you aren't already.

If you are looking at less than 6" of snow, just get a 33" AT tire that is snowflake rated, like the defacto standard, tried-and-true BFG T/A KO2 in size 285/75R16. Like others have said, you can air down to a lower PSI and get a little better traction. They should serve you adequately.

Now, if you are talking serious snow, and your access road (aka driveway) is most likely not plowed, you may need to consider chaining up. With chains, wide tires will limit you, especially real chains like RUD (not those cable chains). Chains will still fit on factory tire sizes, I have the RUD chains and they fit the factory Michelin LTX 275/70R16. While the 33" tires look great and are good performers off road, a factory sized BFG KO2 will perform just as well off road and most likely still accommodate chains (perhaps someone else can verify since I'm not running these tires? ).

Really no reason to change your wheel size. If you have 16" wheels, stick with those. If you have 18" wheels, stick with them, unless you plan to do serious rock crawling and need extra sidewall for tire flex, then you can think about going with 16" wheels. You will see no benefit in running larger than 18" wheels, unless you like to see heads turned with raised eyebrows.

So, if it were me, and the main concern is getting to the property on the mountain top and in the snow, I'd make sure I can put chains on and get narrow (265/75R16) or factory size KO2 (if chains still fit with these). But if the main concern is general off roading, looking good, and snow is secondary, then the 285/75R16 is good for all around.

Let us know what you end up with and how they work out for your application.

 

[joseywales]

There is some good advice in here already. My 100 came with 16” wheels and brand new 305/70 mud tires on it. I traded them for 285/75 BFG ATs. They were great for three years. I’m now running Cooper ST Maxx tires in 255/85-16 and I like the skinnier 255s better in the snow.

You won’t really tell much difference in flotation between any of the 255 to 285 width tires. I’m you go to a 305 or 315 you would notice some flotation. These trucks are heavy, and do not really “float” over anything.

Chains (V-bar or similar) would be a great asset and you can get them for almost any size tire, but just remember that GOOD chains will add an extra 1-1.5” to the size of your tire and you need the wheel well clearance for that. If you have AHC, you may get the extra clearance running in “high” mode. Nothing wrecks a truck faster than using “real” chains that hit the body.

 

[Live to Ski]

Well, if the main use is getting up to his property @ top of mountain in snow, then chains are the ticket.

Are they inconvenient.....sure, but with practice, can install in 10m or less (from my ski patrol experience).

 

[trdcorolla]

I went down this path a few months ago, decided to split all the pro's and con's mentioned above and went 17" wheels with 32" tires. My reasoning is the 100 already felt slow compared to my V8 4runner and it'll be a little easier on the 4spd transmission/drivetrain when I accelerate. Or that's what I tell myself (when I sometimes feel like I should have went 33's).

Update, went to 33's this past weekend.

 

[eurodre]

you can compare the weight of wheels and tires using the info on their respective sites.

Long story short: the difference between 16s and 18s is overstated. Pick one based on your driving style and needs and you're good.