Big Fat Tires - 305/65/18s (7 Viewers)

[TeCKis300]

I posted the below buried deep in a thread. But I believe it warrants its own.

Bringing attention to 305/65R18's. Surprised this size is not well represented on the boards.

On paper, this would be the ideal aggressive fitment, without needing drastic cutting or clearancing. ~33.6" x 12". Solid big meats on stock 18" wheels. With enough visual height and girth to match the full size LC body. My personal opinion, but I dislike narrow fitment tires. It exposes the wheel face to more wear and tear without a meaty wide sidewall. I also value cornering traction as much as straight line tractability.

Only trick would be mild 1" spacers on stock wheels, and minor nip and tuck of the liners and mud guards. I run 33.2" x 12.3" tires rather easily on my LX. The 305/65/18's are only incrementally taller.

Here's my pitch for more beef!

Pics for motivation:

 

[ckkone]

On stock wheels with 1.25" spacers.. I almost went with that size but they cost more weigh more and I didn't want to deal with that much rubbing. I'm also pretty sure you need to change your UCA to run that size because they won't clear the stock control arms...I could be wrong on that though.

Bear, My 200 Series Newbie Build

 

[gaijin]

Solid big meats on stock 18" wheels. With enough visual height and girth to match the full size LC body ... I also value cornering traction as much as straight line tractability.

Three concerns:

- Stock 18" wheels are only 8" wide, but the recommended wheel width for the LT305/65R18 tires you suggest is 8.5" - 11" - stock wheels are too narrow.

- BFG A-T T/A KO2's in that size weigh 62 lbs (and cost US$350/tire). With that much weight at each corner, I don't think you're going to be worrying too much about "cornering traction."

- Will they fit in the standard spare tire location? My LT285/70R17 KO's are already pushing the limit.

Sorry, but they don't look like a good match for the LC200 to me.

HTH

 

[mcgaskins]

Uh oh - a wide vs skinny tire thread! Personally I prefer narrow, but I agree the wider tires look better. Real world experience in the majority of things I encounter, I prefer skinny and tall

 

[TonyP]

Here's a fun read on skinny vs wide

Expeditions West: Tire Selection for Expedition Travel

 

[TexAZ]

I'm also pretty sure you need to change your UCA to run that size because they won't clear the stock control arms...I could be wrong on that though.

I ran this size on my Tundra with stock wheels and had to use spacers to clear the SPC upper arms. When I switched back to stock arms for the sale of the truck, the tires fit without the spacers....

Will they fit in the standard spare tire location? My LT285/70R17 KO's are already pushing the limit.

A 295/70 r18 will fit. Barely. There is a small curved sheet metal piece you have to remove to get it to sit flush.

 

[TeCKis300]

These tires will certainly fit width wise with addition of a 1" spacer on the stock wheels. Or an aftermarket wheel in the +40 or less offset.

Three concerns:
- Stock 18" wheels are only 8" wide, but the recommended wheel width for the LT305/65R18 tires you suggest is 8.5" - 11" - stock wheels are too narrow.
- BFG A-T T/A KO2's in that size weigh 62 lbs (and cost US$350/tire). With that much weight at each corner, I don't think you're going to be worrying too much about "cornering traction."
- Will they fit in the standard spare tire location? My LT285/70R17 KO's are already pushing the limit.

Good points that should be considered.
- The off-road community has been stuffing wide tires on narrow wheels for ages. Yes, it is .5” outside of manufacturers recommendations, but it’s not all that bad. Manufacturers don’t recommend airing down to 15PSI either. But that is where this can also help – the beads are retained better when running a wider tire on a narrower wheel.
- Tire weight doesn't have the impact that most people believe. Loss of acceleration and braking is far more attributed to gearing loss of larger diameter tires rather. It's primary impact is unsprung weight to the suspension, but larger tires themselves do absorb irregularities of the road better. What I can assure you is that upsizing diameter of a 275/285 tire (higher COG), in an AT compound, WILL result in loss of significant cornering performance. Added width WILL certainly do a part to offset that loss and handling performance.
- Yes, they will fit in the spare tire well. I have my 33.2 x 12.3" tire stuff there just fine. With clearance to spare for the slightly taller 305/65R18.

 

[TeCKis300]

Here's a fun read on skinny vs wide

Expeditions West: Tire Selection for Expedition Travel

Ah, glad you bring this up. It's interesting topic that people read at face value, and misinterpret.

From the article:

"the assumption that a taller tire can be fitted to the vehicle if it is narrower

The key instance where a narrower tire has the advantage, is when compared to an equivalent wider tire, of like contact area. And even then, only in certain conditions. One does not benefit from a narrower tire, when giving up contact area. The larger contact area tire will generally have the advantage overall, whether by length or width.

So yes, most people here are upsizing tires, while generally keeping the same width. But for those upsizing tires, and giving up width (i.e. 285 to 275), yeah, that's not an upgrade.

What I'm proposing is that you can upsize the diameter AND width on this platform. And then have an upgrade all around to on road performance, handling, and stability. And off-road traction where additional flotation in sand/snow/mud is really helpful to our VERY heavy rigs.

Not to mention it looks better

 

[TonyP]

It's all entirely dependent on what you're using the rig for. Saying wide (or narrow) is the end all be all isn't exactly the case.

As for tire weight not having a huge impact, the on road manners are profoundly different between my current 285/75r17 which weight over 20 pounds less per tire than the 35x12.5 has had. They're only 0.8 less tall and "only" 2 inches more narrow. Anecdotal? Maybe.

 

[mcgaskins]

So yes, most people here are upsizing tires, while generally keeping the same width. But for those upsizing tires, and giving up width (i.e. 285 to 275), yeah, that's not an upgrade.

Depends on what you're going for, but I would disagree that it's not an upgrade. You've mentioned quite a few times you care mostly about on road handling and you want the biggest contact patch possible. That's great for your use, but it's not a one size fits all. I personally don't care that a 200 doesn't handle like a 911 on the road because that's not its intended purpose.

In my case, the OEM tire measures 31.3" in diameter and has a tread width of 9.3". My 275/65/20 measures 34" with a tread width of 9.2". So I've gained 1.35" in ground clearance and essentially didn't lose any contact patch on the road. Considering my goals/uses of driving on snowy roads (skinnier is usually better), going over obstacles off road (skinnier and taller is usually better) and gaining ground clearance (skinnier and taller is usually better) without having to run spacers, change the upper control arms, swap wheels etc., I'd say it's most definitely an upgrade.

I think there are many "right" ways to upgrade a truck.

 

[RS6tofj80]

I ran this size in Cooper At's on tundra rims - with 1.25 spacers in the rear ( with tundra front).... mild trim to fender liners and they were really nice. actually had them on for a bit before the lift as well. I found they did tend to track or tramline a bit but were a very good fit for the truck, my regret was the AT tire I picked.

 

[Markuson]

My fat/skinny 1.5 cents:

Skinny for cutting into clay-mud that's harder a few inches down (like the jungles of my childhood)...
Skinny for cutting through slushy snow to the road beneath, instead of floating...
Skinny for saving fuel (MPG)...
Skinny helps to avoid hydroplaning in heavy rain...

Fat is great for floating over fluffy sand dunes and just about everything...except MPG.

 

[SWUtah]

285/55/20 BFG AT/KO2’s 10.1” tread width pretty much the same as the 305/70/18 but fit with no rubbing. Just not good if you’re using your rig for rock crawling

 

[TeCKis300]

I'm all for different strokes for different folks. As has been posted, there's pros and cons to each setup.

I just enjoy the fat tired look. A 285 is close, but it's no 305. A 285 sidewall sits pretty flat and square. A 305 has the characteristic bulge. Sure, wheel width has some effect here, but we're all generally running 8"-9" wheels.

Let's just say it's the 305+ / 12"+ club. Check out these 'beauts:

 

[tbisaacs]

#beef

 

[Markuson]

12.5 qualifies...

 

[Arcturns]

I'm all for different strokes for different folks. As has been posted, there's pros and cons to each setup.

I just enjoy the fat tired look. A 285 is close, but it's no 305. A 285 sidewall sits pretty flat and square. A 305 has the characteristic bulge. Sure, wheel width has some effect here, but we're all generally running 8"-9" wheels.

Let's just say it's the 305+ / 12"+ club. Check out these 'beauts:

View attachment 1582602
View attachment 1582603
View attachment 1582604
View attachment 1582605
View attachment 1582617

 

[Arcturns]

I'm all for different strokes for different folks. As has been posted, there's pros and cons to each setup.

I just enjoy the fat tired look. A 285 is close, but it's no 305. A 285 sidewall sits pretty flat and square. A 305 has the characteristic bulge. Sure, wheel width has some effect here, but we're all generally running 8"-9" wheels.

Let's just say it's the 305+ / 12"+ club. Check out these 'beauts:

View attachment 1582602
View attachment 1582603
View attachment 1582604
View attachment 1582605
View attachment 1582617

 

[SWUtah]

BFG AT/KO’s 285/55/20 have a 10.1” tread width 305’s have a 10.2. LX570 wheel rims are 8.5” recommended for 285’s is 9” rims. 305’s recommendation is over 9” rim. So what’s the benefit on a LX to run 305’s?

 

[TeCKis300]

BFG AT/KO’s 285/55/20 have a 10.1” tread width 305’s have a 10.2. LX570 wheel rims are 8.5” recommended for 285’s is 9” rims. 305’s recommendation is over 9” rim. So what’s the benefit on a LX to run 305’s?

Actual sizing does vary from manufacture to manufacture. As they sometimes base various sizes on a single carcass. So one can't always refer to metric sizing, across tire brands/types. I didnt' look at the K02's. For my LX, looking at Falken AT3Ws, comparing a 285/55/20 to my 305/55/20, there's a significant difference:

size, diameter, section width, tread width
285/65/18, 32.6", 11.3", 9.4"
285/55/20, 32.4", 11.2", 9.7"
305/55/20, 33.2", 12.3", 10.4

My personal likes for the beef is added cornering and braking traction. Along with it protecting the rim with a beefier sidewall, and potentially keeps rocks farther away from the body with the added spacers and sidewall. Though it does add unsprung weight.