Tire load index rating

[notents]

I've been reading this forum for some time, and have benefited greatly from the information posted here. I have a question that hopefully somebody can address in reference to the load rating on tires.

I have an 02 Trailblazer EXT with the stock 17" rims that have tires with a load index of 105 (2039lbs) per tire. I am looking to replace those tires with a set that has a load index of 101 (1819lbs) per tire. I realize that my carrying capabilities will be reduced, but I cannot figure out if these tires will still safely carry the vehicle while towing a trailer with a tongue weight of approx.400lbs. (total trailer weight approx.4200lbs.)

Do I need to have the TB weighed to figure out how heavy it is, or can i find that figure elsewhere?

Any guidance would be appreciated.

Thanks, Rick

[loosenut74]

Originally Posted by notents

I've been reading this forum for some time, and have benefited greatly from the information posted here. I have a question that hopefully somebody can address in reference to the load rating on tires.

I have an 02 Trailblazer EXT with the stock 17" rims that have tires with a load index of 105 (2039lbs) per tire. I am looking to replace those tires with a set that has a load index of 101 (1819lbs) per tire. I realize that my carrying capabilities will be reduced, but I cannot figure out if these tires will still safely carry the vehicle while towing a trailer with a tongue weight of approx.400lbs. (total trailer weight approx.4200lbs.)

Do I need to have the TB weighed to figure out how heavy it is, or can i find that figure elsewhere?

Any guidance would be appreciated.

Thanks, Rick

on the vin tag inside the driver door is the actual weight of your truck...

[Jethro]

You are asking to have an less stable vehicle! why would you downgrade your tires??

[notents]

Originally Posted by Jethro

You are asking to have an less stable vehicle! why would you downgrade your tires??

I'm actually looking at a tire with a lower sidewall profile, which will increase the towing capacity by altering the effective gear ratio.

My TB has rearend gear ratio of 3.42 with the stock 245/65R17 tires. By switching to a 255/50R17 the gear ratio will change to 3.74 by giving me a "shorter" tire by 2.5". The tire width will increase by .39".

The highest load rating I can find in a tire that size is 101 (1819lbs) per tire. I guess I'm trying to change the ratio without changing the axle or ring and pinion, and since the truck needs tires, I thought I might be able to get away with doing this.

www.dakota-truck.net/TIRECALC/tirecalc.html is a great source for calculating any gear ratio changes and speedometer/ odometer error when changing tire sizes.