Drivability of 35" tires compared to 33"
- Thread starter rc51kid
- Start date
RMP&O
Expedition Leader
You can drive on 37's just like 31's if the truck is set up right. The only difference you might notice would be in braking. It is all about castor and when lifting an 80 castor goes way out fast. I am running 4" of lift and 35's, which by the way the 35's often look small to me. I think 37's look just right on an 80. Any ways, with 4" of lift and no castor correction items I am out nearly 10* on castor. That is a HUGE amount. Ideally you want castor in the 3-5* range. Me personally, I do not like a mix of castor correction items to get it back to where it needs to be. I like the truck to be set up like stock yet have the larger tires and have correct castor. That is not easily achieved on an 80. Brakes are effected simply due to the rolling mass and weight of larger tires.
So in summary, you can roll with 37's and it can drive just like stock but this takes a lot of work and bolt on items or if like me, it takes fabrication to get right. Put 33's or 35's or 37's on the Cruiser and get castor right. It will drive like you want other than less braking ability.
Oh and I guess there is also the gearing factor. I got 4.10s and a v8 though so do not notice it at all.
Cheers
So in summary, you can roll with 37's and it can drive just like stock but this takes a lot of work and bolt on items or if like me, it takes fabrication to get right. Put 33's or 35's or 37's on the Cruiser and get castor right. It will drive like you want other than less braking ability.
Oh and I guess there is also the gearing factor. I got 4.10s and a v8 though so do not notice it at all.
Cheers
BigSwede
The Credible Hulk
If I may nitpick, it has more to do with the increased leverage of the larger radius tires, although weight does play a role.
RMP&O
Expedition Leader
So I was running 35's on wide alloy wheels. Crappy 35's mind you. I replaced them with new 35's on narrower alloy wheels. Braking got worse. I didn't increase tire size. However, the tires I did buy are heavy, much heavier then what I had.
Cheers
Jwestpro
Explorer
Jwestpro
Explorer
The less something is moving, the less the mass matters but we are mostly talking about moving at a good rate of speed usually in such discussions regarding braking. Thus the weight is actually more important than the leverage due to diameter. Of course having more mass also further out only ads to the issue but you have to remember that the larger diameter is actually rotating slower for the same given speed.
One can easily feel this when changing from a basic oem street tire to something like a BFG AT Ko. The braking system of course matters too.
In 3 different land rovers I have had the pleasure of feeling this difference when going from the oem to a BFG slightly oversized. The biggest "feel" change was in the 96 discovery, then still some very noticeable in the 2004, but in the lr3 with much more modern/overbuilt braking, the change didn't really seem to matter much. I think this is because the lr3 braking is so far beyond what is needed in normal situations that the heavier tire makes less of a % difference and it has adaptable systems to apply more when it feels the need for more.
In the older models it's your leg that has to increase the braking pressure so you feel it more obviously.
BigSwede
The Credible Hulk
Vehicle weight and tire size leverage are both important.
Braking performance will decrease with added weight, of course. But a bigger tire is like grabbing a longer breaker bar to loosen a bolt, you are applying a lot more leverage to the brakes, even if weight does not increase at all. Braking performance will decrease accordingly.
Rotational inertia of the larger tire isn't particularly important, other than the general mass added to the vehicle because bigger tires weigh more. Your brakes can easily stop even a big tire from rotating on its own.
Root Moose
Expedition Leader
Tire weight is a lot of fuss over nothing and overstated, IME.
I've gone back and forth from Swampers to Michelin LTXs to Duratracs all in the same size (265/75-16) and wheels and it made no difference at the seat of the pants or the fuel tank.
Yes, it matters at a theoretical level (in a former life I was a mech eng so I understand the maths) but in the real world it means nada.
The only caveat I'll make is that if you have crap brakes and are underpowered then you might notice a difference.
2¢
I've gone back and forth from Swampers to Michelin LTXs to Duratracs all in the same size (265/75-16) and wheels and it made no difference at the seat of the pants or the fuel tank.
Yes, it matters at a theoretical level (in a former life I was a mech eng so I understand the maths) but in the real world it means nada.
The only caveat I'll make is that if you have crap brakes and are underpowered then you might notice a difference.
2¢
+1
I read about people splitting tire weight hairs in Porsche 911 forums. Reading about it on expedition rigs makes me lol even more.
I went from 35x12.5R18, wheel and tire combined weight of 115lbs to a 35x10.5R18 wheel/tire weight of 100lbs for a difference of 15lbs per corner… and most of the weight difference on the outer circumference.
Acceleration/braking difference was quite noticeable. Easier off the line and better brake reaction. Can't say about fuel mileage since I stopped keeping track.
fireball
Explorer
If you think wheel/tire weight and unsprung mass isn't important you're kidding yourself. They are. Some vehicles are obviously more sensitive to this than others because they lack the power or braking ability to "overcome" the increased weight.
33vs35 tire alone is about 10-12# increase. That isn't exactly splitting hairs. As Hoser mentioned above, 15# makes a pretty big difference! I also applaud him for no longer tracking fuel mileage, it's quite depressing!
33vs35 tire alone is about 10-12# increase. That isn't exactly splitting hairs. As Hoser mentioned above, 15# makes a pretty big difference! I also applaud him for no longer tracking fuel mileage, it's quite depressing!
LandCruiserPhil
Expedition Leader
It has been said that 1lb of reciprocating weight is equal to 10lbs of gross weight
BigSwede
The Credible Hulk
Unsprung mass is important more to the suspension than braking IMO. When I went to 35s on my Trooper I was pleasantly surprised that braking was not affected much. I did, however, notice that stiffer springs were needed to control those big tires on bumps and such.
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Yes. I definitely noticed the difference when going from stock 32s to my 35s. Tire weight and leverage both conspire to increase braking effort, stopping distances, and pucker factor in emergency manoeuvres.
Switching from the original mystery pads to high performance brake pads and fresh rotors made a big difference. For years on all of our street and track machinery we've used Porterfield brand pads and have been very satisfied with the initial bite and fade resistance on the track. The Porterfield R4S street compounds are excellent. We run them in all of our vehicles, and recommend them for all vehicles. Once bedded properly they have incredible performance and life span. Also very rotor friendly. For street use we've easily seen 2-3x the normal lifespan when compared to Genuine Toyota pads.
The 35s aren't THAT much bigger than 33s. About 1.5" overall diameter or 3/4" more diff clearance and slight improvement in approach, depart and breakover angles. Well worth the slight cost premium and fuel consumption increase, IMO.
zimm
Expedition Leader
Pro comp. There was shortage of the goodyear kevlars and i needed a set asap, so i said ******. They gave me a deal. Lateral grip doesnt seem good, but i told the kevlar lateral grip is stinky too. The km2s. Were 80 bucks more a tire, and no one had 5.
Lesson, dont wait till the last minute. Tire stocks are low.