Upgrading to 17.5 inch wheels and tires?

[cariboocreek]

In a previous thread I said I ordered the Good year G614 to replace the stock rubber. All was good until my buddy started telling me about upgrading to the bigger wheel and tire. I have a 351 RSTS with #7k axles and a GVWR of 15,500. I am on the road at around 14,500lbs to 15,000. Weighed at scale several times. The G614's are rated for 3750lbs. Even at 15,500lbs (full load) the tires are carrying about 3100 lbs with a little over 3000lbs of pin weight. I have never had a blowout and am trying to avoid it.

So my questions are:

1. Am I an idiot for not going this route first?
2. Is my buddy an idiot for recommending this route?
3. Am I over thinking this?
4. Are the G614's plenty good enough for my application?
5. Should I switch to decaf?

Thanks in advance for your wisdom....

[norty1]

No, yes, no, yes, yes.

Enjoy your camper. The g614's will serve you well.

[Seann45]

Over thinking..
A safety margin is a good thing but you have a 650 lb safety margin on each tire now.

[cariboocreek]

Well I pulled the trigger on the 17.5 inch upgrade. After finding out that the current wheels on my unit would not support the 614's I really only had a couple of options. As I would have had to change wheels anyway, I opted for a set of 17.5 inch aluminum rims with the Goodyear G114. Total cost $2700. I only spent about $200 more than I would have by upgrading the rims for the 614's, so all in all I'm happy. New wheels and rims are capable of 4850lbs (and 75 mph) so my safety margin just went way up. No clearance issues as the 215/75/R17.5's are actually smaller than the 16 inch set up that came from the factory.

[Paintinfool3]

Dang thats an expensive upgrade ... i plan to upgrade tires eventually but not rims too and although 17.5 rims might look cool the tires that go on them are obviously more expensive also ... post pics before and after for us

[cariboocreek]

My local tire dealer got me the Alcoa 661401 rims with the G114's for $650 installed (plus the tax). I did however get a bit of a deal cause I do lots of other business with them. Typically this would be $800 per wheel.

Mother is going to bit dis-pleased......

[RUSSELL5000]

cariboocreek,

If I understand your post, you have a loaded weight of 15,500 and a pin weight of about 3,000. That leaves 12,500 for your axles to carry, and you have two 7,000 axles for a total of 14,000. 12,500/14,000 = 89.3%; good.

Tires and rims are capable of 4,850 each for a total of 19,400. 12,500/19,400 = 64.4%; good.

If I understand your post, once you decided to replace wheels as well as tires it cost you $200 more to go to the 17.5 from the 16.

Looks to me like you are not close to the capability of the truck; if a single rear wheel, do you push your payload? I assume nowhere near if a dually.



I upgraded my entire suspension system: I went from 4,400 axles to 6,000 axles; 10-inch brake drums to 12 inch brake drums; 15 inch load range D to 16 inch load range E; bronze bushings and wet bolts on spring shackles; heavier gauge spring shackles. Everything, truck included, operates at a little under 80% of specification. I got a TPMS just in case I hit something in the road. Over about 2,000 miles last summer my trailer tires appear to run 5 degrees F hotter than ambient temperature (i.e., cool).

I am trying to determine whether shock absorbers make sense now.

At any rate, my wife, sons, and dogs go without me often while I am at work and then I join up later. I don't worry about the rig and their safety. Worth it to me.

No if I could get everyone else on the road to drive safely.....