Another tire thread - sorry (1 Viewer)

[LBridges]

Sorry to be asking this. But this isn't a lot of info (and maybe experience) out there on this - at least using my search skills...

Anyway, on looking into a new set of tires I saw that Tire Rack is now selling BF Goodrich 285/70-17 KO2s in both the "normal" E load range and a new C load range. The C is listed as being 7 lbs lighter than it's E rated brother.

I have zero experience with a load range C tire.

This is in prep for a 10K mile road trip with the wife. All but maybe 100 miles will be on paved roads, and that 100 would be on something like National Park gravel roads. It's an early May through June western states trip so possible snow at elevations.

Additional point, I have an older set of 275/70-17 KO2 with ~50% tread left, but would like something new and hopefully more reliable. My concern is wasting vacation time waiting on sourcing tire repair/replacements in the middle of nowhere.

Preamble over - questions?

Q1: Could it be worth it to go with a C tire for the gas mileage and potential road compliance, and/or

Q2: Just give up and get some Defenders for that much highway?

 

[Markuson]

Sorry to be asking this. But this isn't a lot of info (and maybe experience) out there on this - at least using my search skills...

Anyway, on looking into a new set of tires I saw that Tire Rack is now selling BF Goodrich 285/70-17 KO2s in both the "normal" E load range and a new C load range. The C is listed as being 7 lbs lighter than it's E rated brother.

I have zero experience with a load range C tire.

This is in prep for a 10K mile road trip with the wife. All but maybe 100 miles will be on paved roads, and that 100 would be on something like National Park gravel roads. It's an early May through June western states trip so possible snow at elevations.

Additional point, I have an older set of 275/70-17 KO2 with ~50% tread left, but would like something new and hopefully more reliable. My concern is wasting vacation time waiting on sourcing tire repair/replacements in the middle of nowhere.

Preamble over - questions?

Q1: Could it be worth it to go with a C tire for the gas mileage and potential road compliance, and/or

Q2: Just give up and get some Defenders for that much highway?

I'd personally get the E.
MPG perspective-- When my 2008 LC was stock...except for 285/70/17 E KO2 on Rock Warrior wheels...I got 18.5-19.5 on the highway. That's despite the fact that it's a larger overall diameter than stock, so my actual MPG would be slightly higher that those numbers. KO2's are light for a true AT.

 

[OverLand Cruisers]

Q1: Could it be worth it to go with a C tire for the gas mileage and potential road compliance, and/or

Q2: Just give up and get some Defenders for that much highway?

Q1: Cs will give you more sidewall flex than Es, and subsequently will do better off road. However I doubt you'll perceive much difference on the highway, or a noticeable MPG increase.

Many folks buy the highest load rating they can thinking it means more puncture resistant sidewalls, not so much. My experience is the opposite, more flex vs. stiff sidewall, etc...

Q2: One thing I prefer about an AT over a dedicated highway tire (Defenders) is better resistance to hydroplaning as there's more room for the water to evacuate. Not huge but noticeable.

We took a 6K+ road trip last year in our 100 with KO2s and they were great.

Sounds like a fun trip!

 

[Markuson]

For what it’s worth...I don’t think you’ll have any trouble getting E’s to flex. You’re not a pickup with low weight in back. You’re in a 3 ton rig even without gear. Air down and you’ll flex your Es.

 

[linuxgod]

Q1: MPG difference will be minimal. Probably more a function of the C load tires weighing slightly less. C load will be slightly softer, which means marginally squishier handling but also marginally less transfer of road imperfections. Then again correct tire pressure for your load has more impact on comfort than sidewall thickness IMO. I tend to run 38psi on my 285/75R17 tires (Gaijin says 37psi is spot on) but when I've run 35-36psi it's significantly more forgiving of city street imperfections. Conversely the 42psi the dealer set them at was super jarring.

Q2: KO2s are pretty easy to source. I wouldn't worry about replacement during a trip. True unlike Goodyear or Firestone not every shop has them but there are enough tire dealers around that do.

I went E load for the slightly thicker sidewall but C load would have probably been fine for me, even when loaded down and towing. If you'll never need to put more than 50psi in your rig (which you shouldn't since that will carry something like 3200# per tire) then I really don't think it matters significantly either way.

 

[TeCKis300]

There's a backstory to the KO2's Load E vs C's. The Ford Raptor is fitted to KO2's from the factory in Load Range C. During Ford's development of the Raptor, BFG had originally provided their standard KO2's in load range E. The story goes that Ford wasn't satisfied with the parameters of that tire, that they went back to BFG to supply a tailored KO2 in LR C.

Most AT tires these days tend to only be available in the max spec load range E. Because consumers rarely understand balance, and reach for the highest, biggest, and largest because they comprehend that to be the "mostest".

Payload is easy to understand. But there's very much tangible benefits in terms of traction, ride quality, and performance that an OEM will be able to measure.

Seems like there's enough demand for BFG to offer the LR C variant of the KO2s in the consumer market. Probably can't go wrong with either spec. I would search the Raptor forums to understand the benefits of choosing one over the other.

 

[gaijin]

Sorry to be asking this. But this isn't a lot of info (and maybe experience) out there on this - at least using my search skills...

Anyway, on looking into a new set of tires I saw that Tire Rack is now selling BF Goodrich 285/70-17 KO2s in both the "normal" E load range and a new C load range. The C is listed as being 7 lbs lighter than it's E rated brother.

I have zero experience with a load range C tire.

This is in prep for a 10K mile road trip with the wife. All but maybe 100 miles will be on paved roads, and that 100 would be on something like National Park gravel roads. It's an early May through June western states trip so possible snow at elevations.

Additional point, I have an older set of 275/70-17 KO2 with ~50% tread left, but would like something new and hopefully more reliable. My concern is wasting vacation time waiting on sourcing tire repair/replacements in the middle of nowhere.

Preamble over - questions?

Q1: Could it be worth it to go with a C tire for the gas mileage and potential road compliance, and/or

Q2: Just give up and get some Defenders for that much highway?

Quick answers first:

Q1: If your choice is between the C-Rated LT285/70R17 KO2 and the E-Rated LT285/70R17 KO2, I recommend the E-Rated version.

Q2: Never give up!

OK, what are the differences between the C-Rated KO2 and the E-Rated KO2?

- The C-Rated KO2 has a Q Speed Rating which means it has a Max Speed of 99mph.
- The E-Rated KO2 has a R Speed Rating which means it has a Max Speed of 106mph.
- The C-Rated KO2 has a 6 Ply Rating.
- The E-Rated KO2 has a 10 Ply Rating.
- The C-Rated KO2 has a Max Load of 2755 Lbs @ 50psi.
- The E-Rated KO2 has a Max Load of 3195 Lbs @ 80psi.
- The C-Rated KO2 is a Blackwall only design.
- The E-Rated KO2 has Raised White Letters on one side.
- The C-Rated KO2 weighs 51 Lbs.
- The E-Rated KO2 weighs 58 Lbs.

And, what are the similarities between the C-Rated KO2 and the E-Rated KO2?

- The Recommended Cold Tire Inflation Pressure is 40psi for both.
- Both go down the road at 635 Revolutions/Mile.

Here's what the Pressure / Load Limit curve looks like for both tires:

Note that the graph for the C-Rated tire ends @50psi while the graph continues to 80psi for the E-Rated tire.

So, what does this mean to you? Well, what's important to you?

I have been running the E-Rated LT285/70R17 KO's for a few years now on both highway and off-road and found them acceptable in both environments. My truck is my only vehicle. Normally, about 40% of my driving is on gravel/unimproved roads (nothing really challenging), about 10% mild off-roading (no air-down required, rarely lock the center diff), about 2-3% slightly challenging off-road (aired down, locked center diff, occasional CRAWL) and the remainder - a little less than 50% - on the highway. The E-Rated KO's are fine for all of this.

But I cheat!

I kept the stock 18" wheels/tires and switch them onto the truck if I am anticipating a highway trip longer than about 5 hours round trip - if the trip is projected to be in good weather. If snow is in the forecast, the KO's stay on regardless how long the trip is planned to be. I don't know if you still have your 18" wheels, but if you do, my recommendation would be to get some nice all-sason highway tires and use them on your 10k mile road trip.

To me, your question really should be:

Should I get a good set of five E-Rated LT285/70R17 tires and use them for everything, or should I get a set of five highway tires specifically for my upcoming road trip?

To me, the C-Rated KO2's make little sense. I wouldn't anticipate any significant gas mileage difference between the C-Rated and E-Rated KO2's. At the same Recommended Cold Tire Inflation Pressure of 40psi, the "spring rate" of both tires (the rate they compress and rebound under load) should be pretty much the same. The 10 Ply Rating of the E-Rated KO2's will make them more puncture resistant and durable off-road than the 6 Ply Rating of the C-Rated KO2's. Also, it makes little sense to me to spend all that dough on C-Rated KO2's when you could have the E-Rated version for about US$10 more/tire.

Sounds like you're doing your homework, but the final choice is yours.

HTH

 

[Sandroad]

For your described upcoming trip and perhaps for the long term use of your '17, I would not consider the Defender to be "giving up". It is a world-class highway tire for the LC, and certainly excellent too for a NP gravel roads. You would not regret the comfort, low noise, and road manners of the Defender. If you regularly tow, or often use your truck in heavy-duty off-road travel, or climb rocks in Moab, then sure, get an AT tire. But otherwise, the Defender seems to me the opposite of giving up!

 

[TeCKis300]

Excellent presentation of facts as always @gaijin ! Good stuff.

Given those facts, I think these are the salient questions:

1) Does one need the capacity of load range E?

- As was presented, required inflation pressure for both tires is 40psi. Load C already offers 20% more capacity margin than is necessary. Load E is quite overkill at 100% more load margin

2) Is a stiffer sidewall desirable?

- Load range E tires has stiffer sidewalls as a result of having an additional poly layer in the sidewall. Note that radial tires don't actually use plys anymore, it's just a legacy equivalency rating rather than construction
- Potentially more sidewall durability and puncture resistance above the Load C tire, which itself is already stiffer and more durable than the OE fitted P-rated tire
- With the same inflation pressures, it's obvious the stiffer sidewall LR E will result in incrementally worse ride quality
- A less compliant sidewall will incrementally affect traction and ride quality

3) Unsprung weight impact?

- High speed handling and traction, both on and off-road, will tip the advantage to the lighter weight tire. Less unsprung weight will help the suspension track an irregular road surface more closely, resulting in better performance. Baja runners have been known to choose the lower load range tire, as their priority is high speed performance.
- Ride quality will be better with less unsprung weight


I personally would opt for a load range C tire if I had a choice in the tire size I was looking for.

 

[LBridges]

Thanks to all for helping me focus on the issues and providing added info to the discussion. Special call out to @gaijin for hitting a home run on what I should have asked...
​

...
Should I get a good set of five E-Rated LT285/70R17 tires and use them for everything, or should I get a set of five highway tires specifically for my upcoming road trip?
...

Haven't made the decision yet. Like much of life it's complicated. My complication is primarily two-fold. 1) I'm cheap and would like to just buy one set and be done, and 2) the wife's DD is an Avalon Limited and she would like the road trip in the '17 TLC to ride as much like her Avalon as possible.

 

[blatant]

The last thing that ever crosses my mind with Land Cruisers is gas mileage... A gas station is it's natural habitat, if you see one not at a gas station, then they're headed to one.

 

[cc1999]

I typically dislike the firmer ride of the E rated tires , about the only thing that comes from the factory with E load range tires is heavy duty 2500 (3/4 ton ) + pickups.

Fuel mileage might be slightly better with C, but as others pointed out most of us didn't buy any of our vehicles with fuel mileage playing much of a factor.

However I do like a smooth comfortable ride though. The 6ply Load range C is really very similar to the P-metric 4ply tires in terms of load ratings, and C's typically ride about as smooth as 4 ply P-metric tires which is what comes on the LCs from the factory.

E's typically do have a noticeably firmer ride.

 

[Itsky]

What did the OP pick? Good discussion!

 

[Itsky]

I would love to get some more thoughts on the pros and cons of the load range C vs Load range E for the BFG AT KO2s in size 285/70/17.

For example if I go with:

-Rock Warriors and load range C BFGs AT KO2s, I'll be at about 76 LBS per corner
-Rock Warriors and load range E BFGs AT KO2s, I'll be at about 83 LBS per corner, or 9% heavier

Pros:
-Saving 9% on wheels and tires, unsprung; slightly less wear and tear, better performance
-Potentially more compliant ride
-trace MPG improvements?

Cons:
-some toughness
-some load carrying ability (could this be realized?)
-Is there enough cushion with the load range C's for this heavy vehicle?

So, if you were buying new tires which would you choose? I'll also note that a set of 5 285/70/17 load range Cs can be had new on craiglist for $850-$1000 as new Jeep Rubicon take offs.

 

[SWUtah]

I put load range “D” 285/55/20’s BFG AT/KO2’s on my 2015 LX570, set the suspension on comfort and it rides like a dream. Put on the “E” rated

 

[LBridges]

What did the OP pick? Good discussion!

The OP ended up going with a set of the C rated KO2s.

My current use of the LC doesn't require the added sidewall strength of a E-rated tire. I have E-rated tires on the LX and the wife doesn't want the LC to be playing in rocks (yet anyway), thinks too much money invested, still too pretty a truck. So I went for a bit of added compliance and weight savings. Just back from ~9K miles of road trip and the KO2s did well in rain, a bit of snow, a bunch of highway miles, and several relatively short unpaved trips mostly in national parks.

Interestingly both the wife and I found the KO2's road noise patterns to be interesting. On some roads they were quieter than the OEM tires, and on some a bit noisier.

I went that way as my local Toyota dealer offered me a good deal, got the 5 new KO2s w/warranty, road force balanced, and with new TPMS sensors for $1120 (plus tax). Still debating what to do with the OEM wheels/tires.

 

[bryson]

Great info here! In regards to the Ford Raptor KO2 in C range (315/70R17) I have some questions since that is the size I'm looking to run.

Normally, I'm in the camp that would run the E-rated version just because I can, but in this case, I can get Raptor take-off tires in near new shape for a very reasonable deal that would put them near half the cost (maybe cheaper even) of their E-rated brothers. My Cruiser sees way more highway miles relative to off road than I'd like to admit, but not that many of each really. But, very luckily for me, a trip to Moab is only 3.5 hrs on the highway, the San Rafael Swell is 2.5 hours away, local mountain trails are 1 hour or less, etc...

I don't know the load indexes of each tire without looking, but my rig isn't heavy (for a Cruiser) and if I tow, it's only 3-4k lbs max. I'm assuming at this point since the Raptor weighs ~5800#, has the same 8k tow rating as a 200 that I shouldn't worry too much about the tire not being tough enough.

So, 315/70r17 load range C on RWs on my 2008 200... Thoughts?

 

[gaijin]

So, 315/70r17 load range C on RWs on my 2008 200... Thoughts?

Too big.

 

[bryson]

Too big.

Ha ha... yeah, I do understand that part, and will deal with it accordingly. Any thoughts strictly related to the safety, durability, etc. of that tire on my Cruiser?

 

[SWUtah]

Ha ha... yeah, I do understand that part, and will deal with it accordingly. Any thoughts strictly related to the safety, durability, etc. of that tire on my Cruiser?

Post a picture when you get them installed I think you’ll be the first one on the site with that tire wheel combo