A question on LT tyres

If you want to go off road....then LT is the way to go..

As per the speedo......who says your speedo is correct now ??

As per fuel economy......a tyre is black and round....and any difference between a LT and a HT would be so miniscual it wouldn't be able to be measured ( assuming the size was the same !! )

Isn't LT referring to the construction rather than the type of tyre.
ie: LT = Light Truck. Supposedly a heavier duty construction. (Unless, of course, if you are referring to Cooper tyres, then it makes no difference).

HT, AT & MT refer to the style of tyre, so you can have an All Terrain (AT) tyre, of Light Truck (LT) construction.

Hi Rich
LT means Light Truck construction (Heavy Duty), you need to run your tyres at a higher pressure ie: my 04 Patrol runs min 40psi now compared to 32 to 36 for passenger construction tyres.
Rob

Richard, as others have alluded to..

LT means light truck, it is the way that the tyre is constructed - usually heavier sidewalls for a start.

Using the Bridgestone AT Duellers as an example.

you can purchase a 694 (model of tyre) in an AT (all terrain tread pattern) in either a passenger OR light truck construction.

The size and tread pattern is exactly the same, the way that the rubber and plies are constructed is different. Therefore there 'should' be no change to your speedo assuming that you purchased the same tyre size.

If you do a lot of driving on rocky roads with sharp schist type rocks the LTs will give a longer life and much better puncture resistance.
They have stiffer side walls as well and are less susceptible to side wall staking

An example, I drove the Gibb River road, Arkaroola road with bridgstone Dueller ATs LT. Mate drove the same tracks with me with Straight Dueller ATs. He had 5 Punctures and one blow out on brand new tyres. I had nothing at all on tyres that had already done well over 50,000 kilometres.

Fuel economy won't change.

The only difference you may notice is the AT or LT tyres may not be as quiet on the bitumen.

Bill

Sandman,
Many thanks for the reply, you have answered my question re fuel economy.


To others many thanks for info, unfortunately my knowledge and terminology were a bit off (ok a long way off).

May be some background on my question will help
I am planning a trip up to Cameron Corner and down the Strz and am towing a camper.

For awhile until I hit the road, a part from this and a few other outings, I will be doing bitumen so was concerned over economy (false as it may be)

I did not have a realistic option to swap out my H/T tyres when I got the vehicle (12 months ago) and am looking now for a AT passenger consruction or a LT construction tyre (hopefully I have it right now - wanted to sort it out before talking to dealers)

As I want to take a second spare with me it would be beneficial to match my current tyre profile (265/65 R17) as it would mean I only need to buy 5 new ones and keep the old ones as spares. Unfortunately you can not get an LT tyre in this size. To go LT I need to go to a 265/70 profile.

Going to this profile will take me over the 15mm rolling circumference size. This is legal for a 4wd where I am from as you can go up to 50mm (4wd only). However if you do (ie go over the 15mm) then you have to get your speedo recalibrated - I got this from the car leasing/insurance company. As said in another post, going to the larger size will actually make the speedo more accurate - based on other peoples experience.

So I have to make a decision - do I stay with the HT or go to a AT (passenger construction with same profile) or go to an LT where I will have to buy 6 tyres and get a speedo recalibration.

As part of my decision making I am trying to get info on the impacts of using LT tyres (which I agree is probably the best option but not the only - I think:)).

Hopefully the above gives you an idea where I am coming from and why I have asked a strange question.

Once again to all many thanks for your comments,
Richard

Richard,
Thanks for the reply.

I agree with what you say about the speedo.

The issue I have is that the leasing/insurance company will not approve the new tyres unless a recalibration is done officially - I have asked them.

It is just another cost unfortunately after which it is forgotten.


Richard

What nobody has mentioned and is the most important thing of the lot is that LT tyres generally have a higher load rating per tyre than car tyres or NON LT.
No one really should consider the non LT if putting capacity loads in a 4 WD.
They will restrict your loads and towing ability as well if its getting up there and as they say have a much stronger construction.
Look on the sidewall as all tyres have the load rating at a certain pressure moulded into the tyre

If I was going to those places you mentioned....and I was putting new tyres on the 4x4 then I would defineately put on an A/T of L/T construction..

As for the lease company? Tyres will be legal but they want the speedo recalibrated ? They ARE a strange lot ??

What size do you have on now?? Would be unusual if they don't make an A/T of the same size ??

Use this to compare sizes and diameters and anything else

http://www.rims-n-tires.com/rt_specs.jsp

Hi Richard,

I am assuming here that this is a 120 prado with those size tyres.

I have a 120 Turbo-Diesel and on day one I fitted 265/70R17 Cooper AT's. My leasing company (Toyota Financial) paid up for them with no drama. It was the Tyre dealer that made the phone call to get them authorised and they did not ask details, just the price.

I have since worn those out and had them replaced with Cooper ATR's in the same size. These are the LT version and I am extremely happy with their wear rate and the performance on bitumen and moderate gravel. I have a second set of Goodyear MTR's (in the same size) for serious 4WDing but the ATR's would be great for anything the Corner Country could produce.

On your original question, yes the LT's use slightly more fuel than passenger tyres due to being stiffer and having a higher rolling resistance. The original Cooper AT's wre P construction and when I went to the LT ATR's the fuel consumption went up slightly.

When I put the MTR's on the car they chew an extra 1 to 2 litres per 100/km due to being stiffer again than the ATR LT's. I would not think the difference between P and LT ATR's would be quite this much but would be close to 1 litre per 100km.

I am surprised your leasing company is so stringent on the regs when my experience has been that even the tyre dealers rarely mention such matters! Certainly my leasing company have been willing to just accept the professional opinion of the Tyre Dealer in specifying tyres for my vehicle.

That's my thoughts and experiences. Best of luck with it. My approach with this stuff is to be informed (via sites such as this one and some of the govt sites) but play it a bit dumb at times. Sounds like you asked too many questions at the leasing company and now you are stuck with the 65's!

Also be aware that Federally the rules have changes to allow a 50mm diameter increase in wheel/tyre combos but not all states have adopted this yet.

Google is your friend here!

Cheers
Muddy

Yokohama ATS..265/65/17.....doesn't state whether they are LT or not but there are plenty of them getting around the outback on Cruisers and traytops !!