Lt Tire Factory Option On A 1500 Truck

[pm26]

Today I saw a new 2008 extended cab 4X4 1500 Silverado truck with the factory LT tire option. This is the first time I saw this as it is not very common around here. Anyway, the tires were LT245/70R17, instead of customary P265/70R17. They had a more aggressive tread and were designated as "all terrain" tires. They were Firestone tires, but I did not notice which brand. Anybody knows what GM uses on these trucks?

 

The truck had 3.42 axle ratio and using somewhat narrower tires like these will effectively change the gear ratio to something like 3.55:1. Using tires like these is one option for those who have 3.42 ratio axles and want a bit more torque a the rear wheels for better power and acceleration without doing anything else. Yes, you need smaller tires for better power, not larger tires!!!!!

 

Are these high pressure tires, like 80 psi? I test drove the truck and I actually liked the ride these tires provide. Very smooth and responsive.

[alaska511]

I had asked the dealer about this when I was shopping for mine, and the answer was that the P tire was the only option for the 1500. I checked the site to see if anything had changed, and I cannot find any LT tires as an option there, either.

 

I was told the LT tires were on 2500 and heavier trucks.

 

Did it state this on the sticker? All you can do is ask the salesman, and then read the tire to see what load range they are. If they are E rated you will see they have a max 80 psi.

 

If they are C or D it will be a lower max fill pressure.

 

If it isn't on the sticker, I would suspect they were dealer installed.

[pm26]

No, they were listed on the sticker as a $ 200 (approx) option.

 

The option was described as:

 

LT 245/70R17 BW AT tires,

 

which I assume means "light truck black wall all terrain tires."

 

It is possible that these are only available on extended cabs and not on crew cabs.

[MS3DALE]

"LT" tires have been an option on 1/2-ton trucks for years now,The problem is though....they weren't available every year.

They use Firestone Transforce A/T's in a load range "C" on the GMT900 trucks.

 

They were also available on most of the "early" GMT800 trucks also,They used Firestone Steeltex A/T's in an LT245/75R16 size,In a Load Range "C".

They were also available on the GMT400 trucks as well,in the same size and load rating,The later model years,say '95 to '98 used the same tire (Firestone Steeltex A/T) and if I remember correctly the early models ('88 to '94) used some kind of General Ameritrac tires on them.

[c4cruiser]

Looks like there is at least an inch difference in diameter between a 245/70-17 and a 265/70-17. this would effecively create a lowered gearing by going to a smaller tire, but simply changing to a shorter 245/70 on a truck already equipped with a 265/70 could have negative impacts on some vehicle systems. The speedo/odometer would be off and possibly some systems that depend on a proper VSS signal to the PCM would be confused.

 

Firestone's website and the Tire Rack website section for Firestone really doesn't show a lot of choices for either size in a LT "all-terrain" tire. Looks like only a Load Range C tire with a 44 psi max inflation pressure in a highway rib tire is available as an LT rated tire.

 

GM may have contracted with Firestone to produce an OEM tire LT All-Terrain tire and tread pattern for the Silverado/Sierra that is not otherwise available at the retail level.

[MS3DALE]

Guys.....Let me make a correction to my earlier post,I went up and looked on our lot,The Firestone LT tires on these trucks are "Transforce A/T's" NOT Destination A/T's. My bad!

I also edited my earlier post.

 

You'll find it here,Its the 10th one down on the list.....Transforce A/T

[pm26]

The LT tire is 1.3 inches less in diameter, or 4% less than the P265 tire. Because the rear end gearing is directly proportional to the tire diameter change, this will effectively increase the gear ratio by 4%, or from 3.42 to 3.55 as already stated.

[50usilverado]

had these tires on my 2008

[My2007Silverado]

These are the factory tires on my 2007 new style LT2 Silverado.

Definitely a nice riding tire, with pretty decent wear. I wish they were the 265s but will run 'em until they wear out. Have over 100K KMs on them now - still look pretty good

 

had these tires on my 2008

[wzschirnt]

Actually, isn't the RADIUS that is the important measurement as far as gearing goes? So that would be about .65 of an inch. Not too much difference to worry about IMO. Diameter (circumference, actually) for mileage, etc.

 

 

Later.

[redvett]

Just remember "LT" tires weigh more than a "P" tire and cause more rotational losses in fuel economy.

[jtramsey]

Would going from a 245 to a 265 change the gearing on a 3.23 ratio?

[Ryan00TJ]

Would going from a 245 to a 265 change the gearing on a 3.23 ratio?

 

Yes, 4% either way. My truck was optioned with these tires and they are a good tire. I am at 18K miles and they are half worn. They are quiet, ride nice, decent all around traction from rutted gravel roads to 8" fresh snow. I would really consider buying another set when they wear out but they are not made in a 275/70/17 I am going with.

I like the fact they are LR C 6 ply. Perfect for a 1/2 ton. There is no need for a E rated tire on a 1/2 ton.

BTW with the 245's and 3.73 rear it makes for a relative gear ratio of 3.90.

[kawtoy_77]

Here's some thing to think about

 

^P-rated tires are lighter = less rotating mass which provides better fuel economy.

 

^You can get tire in P-series, that will handle more/less weight

(for ex. my fiance's dad has tire 1090lbs/tire load rating, and mine are 2535lbs/tire load rating, but both are a P-series)

 

^LT tires are more expensive than P-series tires

 

So if you can get away with running a P-series tire on your truck; i.e. you don't do any heavy hauling or trailer pulling.... Why wouldn't you run a P-series tire?