How big is too big?

Brownie

Forum Member
Joined
May 28, 2018
Messages
12
Location
NSW
Car Year
2005
Car Model
Forester
Transmission
Manual
I want to upgrade my wheels and I was looking at fitting 215/70R16 A/TS (possibly 215/80R16 if it would work) I was planning on combining it with a 2 or 3 inch lift. Sorry if this is a bit of a silly question, I am new to all of this and want to learn
 
G'day & Welcome Brownie


21565R16 is a common upgrade as your tyre size is limited by the spring perch because it's position does not change with a strut top lift.


There's a couple of sticky threads that you may want to look at above.
 
don't forget the legalities in NSW, either.

< 7% diameter change without certification.
 
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The bigger you go the ince going from more strain you put on everything & the worse your ability to climb will be.


I've noticed since going from 215R6016 to 21565R16 that I have to drop back a gear sooner when climbing.


If you want more rubber, consider dropping a rim size to 15", then you'll be able to get MTs on it. :)
 
You have a SG Forester which has the higher spring perch. 215/70/16 is by far the most popular size for lifted Foresters & with a 2" lift will fit without rubbing.


225/70/16 will also just squeeze in under the spring perch but you'll need to flatten the pinch weld behind the front wheels, possibly a little trimming in the rear too


For tyre regs, the 7% rule doesn't apply to Foresters or Outbacks in Victoria, NSW & Queensland. In these states, you're allowed tyres with 50mm bigger diameter giving 1" tyre lift. This is in addition to 50mm strut lift, ie 75mm total lift is completely legal! Unfortunately, this doesn't apply to other Subies or other states. Hopefully, as they keep updating the laws, all the other states will come into line
 
NachaLuva said:
You have a SG Forester which has the higher spring perch. 215/70/16 is by far the most popular size for lifted Foresters & with a 2" lift will fit without rubbing.
Click to expand...


Mine rub slightly on something on full lock and they're 215/65/16... .


Well.. something makes a noise anyway. maybe it's my steering.:sadbanana:
 
NachaLuva said:
225/70/16 will also just squeeze in under the spring perch but you'll need to flatten the pinch weld behind the front wheels, possibly a little trimming in the rear too
Click to expand...


Just squeezing in is not really good enough because with tyre flex your tyres will rub on the spring perch; mine did!


Ben Up North said:
Mine rub slightly on something on full lock and they're 215/65/16... .:sadbanana:
Click to expand...


So did my 21565R16s; they rub on the inner wheel arch.
 
NachaLuva said:
215/70/16 is by far the most popular size for lifted Foresters & with a 2" lift will fit without rubbing.e
Click to expand...


Lifted or not they should still fit - not that I recommend that size of course.
 
Ben Up North said:
Mine rub slightly on something on full lock and they're 215/65/16... .
Click to expand...


I'm surprised they're rubbing, 215/70/16 don't rub for most people depending on the brand


Kevin said:
Lifted or not they should still fit - not that I recommend that size of course.
Click to expand...


A lift kit doesn't stop tyres rubbing on the spring perch of course, but it does stop them rubbing on the wheel arch with the suspension compressed like when you go over a rut
 
Would an offset wheel help avoid rubbing do you think?
 
the bigger wheels the less power you get to wheels. so you making it worse with too big wheels. looks good maybe but not drive as it could.
 
True, but I think my biggest concern is the gear ratio as low range would go faster than normal which isn't nice.

90% of my driving is rural highway driving in 110km zones. Do you think the bigger wheels would increase or decrease fuel efficiency at cruising speeds like that?
 
Brownie said:
Would an offset wheel help avoid rubbing do you think?
Click to expand...


To a certain degree it would help to move the tyre away from the slope of the spring perch; over in the USA many people fit wheel spacers which are illegal here.
 
Brownie said:
Would an offset wheel help avoid rubbing do you think?
Click to expand...
If you fit 215/70/16 you don't need low offset wheels or wheel spacers, they clear the spring perch on factory rims. Even 225/70/16 just barely clears. 215/70/16 all terrains is by far the most popular size for lifted Foresters, literally 1000s of people are running them

225/70/16 ATs on Toyota 86 rims (+48, same offset as your Forester rims) with 2.5" lift:


215/70/16 BFG KO2s on factory SG XT rims with 2.5"/3" lift"


215/70/16 BFG KOs on factory SG XT rims with 2" lift & Pedders HD springs:
 
Brownie said:
Do you think the bigger wheels would increase or decrease fuel efficiency at cruising speeds like that?
Click to expand...


Bigger more aggressive tyres will affect fuel economy. If you want ATs maybe if you fitted something like Bridgestone AT D697s rather than, say, BFG ATs would have less impact on fuel usage.
 
Going from 60 to 65 series makes a bit difference in performance particularly if you are doing a lot of high country tracks. Going bigger I.e. 70 or 75 series you run the risk of getting stuck on a steep climb.
I changed my diff ratios and low range which has overcome this issue.
 
How did you change your low range ratio? I didn't know that was possible
 
Brownie said:
How did you change your low range ratio? I didn't know that was possible
Click to expand...
Low range from the SF gear box, 4.44 diffs front rear and a .738 5th gear.
You cannot believe the difference in both hi and low range. Also the torque is in a more usable rev range.
 
havachat said:
Low range from the SF gear box, 4.44 diffs front rear and a .738 5th gear.
You cannot believe the difference in both hi and low range. Also the torque is in a more usable rev range.
Click to expand...

I'll have to keep that in mind! And an eye out for an SF gearbox!
 
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