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Oregon 07-23-2016 01:32 PM

Move to larger tire size??
 
I have a 2016 Forester 3011DS, which comes with 16in tires.

Was wondering if anyone has upgraded their tires and wheels to a larger size and what (if any) effect it had on handling, performance, ride, etc etc. ???

Research (google is my friend) says that I most likely want to stay with same wheels but can go up in size by 1in (to 17's). Should increase ride and handling without much change in performance (or sppedo).

Wonder what others have found out.
All comments and suggestions appreciated.

Tireman9 07-23-2016 01:41 PM

Quote:

Originally Posted by Oregon (Post 1268024)
I have a 2016 Forester 3011DS, which comes with 16in tires.

Was wondering if anyone has upgraded their tires and wheels to a larger size and what (if any) effect it had on handling, performance, ride, etc etc. ???

Research (google is my friend) says that I most likely want to stay with same wheels but can go up in size by 1in (to 17's). Should increase ride and handling without much change in performance (or sppedo).

Wonder what others have found out.
All comments and suggestions appreciated.

Your #1 concern is Can you go up in size and have equal or greater load capacity. I am guessing you have something like LT235/85R16 LR-E

What are your measured load on F & R axles?

What performance do you not like with current tires?
What is your current Cold Inflation pressure

I have a number of posts on my blog on tire size and how to change.

Don't know how you "stay with same wheels but can go up in size by 1in (to 17's)"

Speedo is directly affected by tire OD.

I bet the web sites you were looking at were talking about changing size for passenger tires not LT tires.

Kenny kustom 07-23-2016 02:47 PM

As long as your tire overall diameter doesn't change, your speedo will be correct. Saying that, to keep the same od, you will have less sidewall.
Thus making for a stiffer ride.


2016 Sabre 36QBOK
2015 Ram 3500 CUMMINS

ChooChooMan74 07-23-2016 03:00 PM

I would throw a suggestion out there. Rickson Wheel 17.5" wheels. Not cheap, but the way I would go.

Rickson Wheel Manufacturing

http://www.ricksontruckwheels.com/im...er-with-17.jpg

Tireman9 07-23-2016 08:02 PM

Quote:

Originally Posted by Kenny kustom (Post 1268076)
As long as your tire overall diameter doesn't change, your speedo will be correct. Saying that, to keep the same od, you will have less sidewall.
Thus making for a stiffer ride.


2016 Sabre 36QBOK
2015 Ram 3500 CUMMINS

Same OD but bigger wheel = less load capacity. I am guessing you are near the max already

HappyGuy 07-24-2016 05:29 PM

I would steer clear of cast aluminum wheels. They will be heavier and as the other op stated, will likely not be able to carry the same load.

17 inch forged Alcoa wheels will hold more weight per wheel than the current steel wheels and the net weight gain should be negligible. A forged aluminum wheel will drop unsprung weight when holding the same size and will normally allow you to go up one wheel size without a large weight penalty and a reduction in CCC. Every pound you add in unsprung wheel weight will drop your CCC by 4 pounds. Aluminum wheels have been reported to give a smoother ride thanks to their trueness. I looked at a wheel swap myself, sticking with the same size wheel. A same size swap would net an 85 lb drop in unsprung weight. Going up an inch in size added a few pounds per wheel but the added material in the tires needed to carry the same weight would cause another bump in unsprung weight for the aluminum wheel / tire combo. The replacement inner steel wheels will add some weight on top of the added rubber weight. IMO increasing the rim size just wasn't worth the potential loss in 100 - 200 lbs of CCC.

If you're planning on upping the brakes, spring packs, axles etc to punch up the CCC capacity to the old E550 stats then the rim swap would make some sense. Of course that would be the cheap part of the work at that point

http://media.automanager.com/wmphoto...3db68f_640.jpg

The major down sides to a forged aluminum wheel are:

A lack of wheel selection

Cost (1200 - 1600 for a set of 4 16" wheels)

Added thickness of the rims prevents using 4 on the back due to a lack of wheel stud length, wheel well

Aluminum tends to fracture instead of bend. If you smack a curb hard enough to bend a steel wheel you might end up destroying the aluminum wheel. The steel wheel can be repaired, the aluminum wheel will likely need to be replaced.

Kenny kustom 07-24-2016 09:12 PM

Quote:

Originally Posted by Tireman9 (Post 1268307)
Same OD but bigger wheel = less load capacity. I am guessing you are near the max already


Not necessarily.
I could put 19.5's on my ram, and jump up a fair bit in load capacity with g rated tired.



2016 Sabre 36QBOK
2015 Ram 3500 CUMMINS

gamidon 07-25-2016 08:09 AM

I have the same unit and just found out I have air shocks. This may help your ride. My unit appears to bottom out on large bumps.

mnoland30 07-25-2016 04:36 PM

Section Height
 
I'm a big believer in section height. That is the distance from the ground to the rim. That rubber and air gives you a cushion as you drive down the road. I've never seen a reason for larger rims, but love more clearance and cushion.

mnoland30 07-25-2016 04:37 PM

Also, I find 16" tires to be a little cheaper.

Tireman9 07-27-2016 03:20 PM

Quote:

Originally Posted by HappyGuy (Post 1269144)
I would steer clear of cast aluminum wheels. They will be heavier and as the other op stated, will likely not be able to carry the same load.

17 inch forged Alcoa wheels will hold more weight per wheel than the current steel wheels and the net weight gain should be negligible. A forged aluminum wheel will drop unsprung weight when holding the same size and will normally allow you to go up one wheel size without a large weight penalty and a reduction in CCC. Every pound you add in unsprung wheel weight will drop your CCC by 4 pounds. Aluminum wheels have been reported to give a smoother ride thanks to their trueness. I looked at a wheel swap myself, sticking with the same size wheel. A same size swap would net an 85 lb drop in unsprung weight. Going up an inch in size added a few pounds per wheel but the added material in the tires needed to carry the same weight would cause another bump in unsprung weight for the aluminum wheel / tire combo. The replacement inner steel wheels will add some weight on top of the added rubber weight. IMO increasing the rim size just wasn't worth the potential loss in 100 - 200 lbs of CCC.

If you're planning on upping the brakes, spring packs, axles etc to punch up the CCC capacity to the old E550 stats then the rim swap would make some sense. Of course that would be the cheap part of the work at that point

snip

The major down sides to a forged aluminum wheel are:

A lack of wheel selection

Cost (1200 - 1600 for a set of 4 16" wheels)

Added thickness of the rims prevents using 4 on the back due to a lack of wheel stud length, wheel well

Aluminum tends to fracture instead of bend. If you smack a curb hard enough to bend a steel wheel you might end up destroying the aluminum wheel. The steel wheel can be repaired, the aluminum wheel will likely need to be replaced.


I would not worry about CCC unless you are at the GAWR or GVWR of the RV. I understand the disadvantages to unsprung weight as it means something in a race car but for RV I think the unsprung / sprung weight topic will just confuse many.
When you weigh a truck or RV it is the total load on each tire as measured on the scale. The tire capacity is not affected by sprung or unsprung loading.

Tireman9 07-27-2016 03:25 PM

Quote:

Originally Posted by Kenny kustom (Post 1269412)
Not necessarily.
I could put 19.5's on my ram, and jump up a fair bit in load capacity with g rated tired.
2016 Sabre 36QBOK
2015 Ram 3500 CUMMINS

Since it is the inflation that carries the load not the tire moving from LR-E two steps to LR-G is where the extra load capacity comes from.
The OP didn't provide his tire size (would be helpful) but I am guessing it is LT235/85R16 LR-E which is rated 3,640# @ 80 psi in single position and is about 31.73 OD.
There are no LT sizes I am aware of in 19.5" but there are Truck tires in that rim diameter with an 8-19.5 LR-F rated at 3,525# at 110 psi but it is 33.82 OD so that can't be it as the load capacity is lower.

What size 19.5 are you thinking about?


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