Tire load index rating

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

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

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

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.