I have a 2005 trailblazer 4x4 that needs new tires. The tires that are on my blazer are p245/75r16. A mechanic friend has 4 new tires that are p235/70r16 that I can get incredibly cheap. just need to know if these tires will work. He says the only problem is they will make my speedometer off by about 5 mph and the tires will be loud against the road. That orries me!My son just started driving and he drives my blazer. Don't want him to be in something that is not safe!
Don't want them if its going to cost me more in the long run.

 

IMO tires have no "low bidder" as they can cause you grief, or save your life. What I read is the speedo will be off, with different size tires true. I'd not only look at the ply, but age (used) and sidewall rating.