[FC] Help choosing tires -

Sat Oct 24 21:54:15 EDT 2009

The poor list of choices and the narrow stock rims were two of the 
things that pushed me toward the 15" solution I ended up with.  The 
other factors were low cost (mine are steel wheels out of the boneyard) 
and desire for less sidewall flex.  The rims I'm using were from early 
'80s mid-sized GM station wagons.  I think some of the larger FWD cars 
of the 80s and early 90s might use similar 15x6 rims with small chevy 
pattern..  If you're shopping aftermarket, a rim designed for an FWD 
sedan might be just the thing - the offsets tend to be about what you 
need for an FC Corvair.  For the record: the rolling radius of a 
205-70-15 is within a couple of inches of the original 6.00-14 tires.  
My odometer is accurate within 3 percent without any adjustments.

205-70-15s are available in a lot of varieties for use on sedans and 
light trucks.  Initially I ran all-season tires, until I decided that I 
would essentially never need high traction, but did want a little less 
tread noise, then I went with sedan tires.

They definitely handle better than tires on stock rims because of 
reduced sidewall flex.  One detail point worth considering: since you 
have swing axles, you need to avoid tires with a square tread 
cross-section when shopping.  The tire will go from plenty of adhesion 
when the axle is level to very little when the suspension deflects 
either direction.  A rounder tread cross-section is always better.  
This, along with ride quality, is what keeps me from trying lower 
profile tires on 16" rims - generally, the lower the tire profile, the 
squarer the tread cros-section.

-Rad Davis

Dale Dewald wrote:
> Hello Jeff,
>
> At 17:22 10/23/2009 -0500, you wrote:
>   
>> Folks - I'm getting ready to put some tires on my '64 Greenbrier. I'm using
>> stock rims.
>>
>> 1) What sizes have others had good experiences with?
>>     
>
> I and many others have used P205/75R14 tires on stock rims and they have 
> worked okay, but these are not the best fit for the rather narrow 5" wide 
> stock rim.  Make sure to check the manufacturer specified rim widths before 
> purchasing them.  Some other people have used P195/75R14 but I worry that 
> these do not have an adequate load rating to support a fully loaded or, 
> quite frequently, overloaded FC.
>
> The 1964 Shop Manual Supplement pg 3-6 lists the types of 7.00-14 tires and 
> inflation pressures for the Corvair 95-1200 series.  It is interesting to 
> note that the standard tire, 7.00-14 4-ply SP (special purpose) [35psi 
> max?] is not a standard load passenger car tire, but a reinforced sidewall 
> (special purpose) tire.  A 6-ply SP tire was optional [39psi max?] as were 
> LT (light truck) 6-ply [50psi max] and 8-ply [65psi max] tires.
>
> Tim Schwartz of NJ has been extremely satisfied with the 185R14 and 195R14 
> sizes designed for European minivans; e.g. VW Vanagon, Eurovan, Renault 
> Espace, etc. I think these are about as close as you can get to the OEM 
> optional tires with respect to size, construction and load capacity.
>
> Check this link for the Continental Vanco 2, a load range D tire (8-ply LT) 
> designed for 65psi max inflation:
>
> http://www.tirerack.com/tires/Spec.jsp?make=Continental&model=Vanco%202&partnum=8QR4V2&vehicleSearch=false&fromCompare1=yes 
>
>
> or the Yokohama Y356, a load range C tire 6-ply LT) designed for 50psi max 
> inflation:
>
> http://www.tirerack.com/tires/Spec.jsp?make=Yokohama&model=Y356&partnum=8R43566&vehicleSearch=false&fromCompare1=yes 
>
>
> A very excellent tire discussion is contained on this VW Bus site:
> http://www.ratwell.com/technical/Tires.html
>
> I have searched a lot of tire company web sites but have not come up with 
> true replacement for the original 7.00-14 SP 4-ply tire standard equipment 
> OEM tire.  I imagine that the modern designation for such a tire would be 
> something like P195/80R14ref 97T.
>
>   
>> 2) For future reference will 15 inch rims fit?
>>     
>
> I have a set of 15X6 reproduction Corvette rally wheels on our '65 
> Greenbrier.  Most GM RWD 15X6 wheels will fit and some 15X7 wheels will 
> fit, but they must have the correct back spacing.  Other people could 
> supply more specific recommendations.
>
> The 15X6 wheels on our Greenbrier are fitted with P215/65R15 (96 load 
> rating) tires which have a slightly higher load capacity than the 
> P205/75R14.  I have been fairly happy with them and with the size which is 
> very near the stock 7.00-14 for rev/mile (about 800).  It is now time to 
> replace them, so I plan to follow Mr Schwatz's example and mount 
> 215/65R15XL (100 load rating) or 205/70R15 (104 load rating) tires, which 
> are sizes also used on European vans.  I am considering either the Nokian H 
> or WR C Van.
>
>   
>> 3) I haven't see much as far as recommended tire pressures for the vans,
>> could someone fill me in.
>>     
>
> Your tire pressures should follow the recommendation of GM, but take into 
> account modern tire construction and the maximum inflation pressure for the 
> tire at rated load.
>
> The Vanco2 and Yokohama tires mentioned above are load range D (8-ply) and 
> C (6-ply) LT type tires. I think you could safely use the original GM 
> specified pressures and adjust them slightly to meet your driving 
> conditions. Tire manufacturers make a limited selection of REF (reinforced) 
> and XL (extra load) tires in 15" and 16" sizes that I think correspond to 
> 4- and 6-ply SP tires originally specified for the FC.  I think these could 
> be used in similar fashion.
>
> What about using standard load passenger car tires?  When I ran 
> P205/75R14's on our Greenbrier I set the cold pressures at 31/35 F/R to 
> compensate for softer sidewalls and marginal load capacity of these 
> passenger car tires.  The P215/65R15 tires were V-rated with a maximum 
> inflation rating at 51psi, so I ran them at 44/48psi F/R.  A lot of newer 
> tires are rated for 44psi at maximum load--you will have to check the 
> sidewall. If these are standard load rated, I would run them near their 
> maximum pressure; 38/42psi F/R.
>
> I'm sorry to not give you a more simple answer.
>
> Dale Dewald
> Hancock, MI
>
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