A "tiring" decision

[Vinn]

Hey CAC’ers,

I'm trying to decide what to do with the tires/wheels on my 70. Right now I have the stock rally wheels with BFGoodrich Radial T/A tires (225/70/15). Well these tires look great but to the best of my knowledge they’re over 20 years old so it’s time to replace them.

Here’s my first big decision: Do I stick with the old 15” rallys or upgrade the wheels for a more modern tire. If I upgrade, I’d go with the steel 16-17” rallys (aluminum is probably out of budget) so I can use the same hubcaps and retain the stock look which I like.

What are the major benefits of each decision? I see the potential for pros and cons each way. I’d love to hear others experiences. There’s a wealth of information on this site about tires for each size and I may need some help on that once I decide which route to go.

Oh, one last thing… when I turn the steering wheel full lock, the current wheels rub on the wheel well. I plan on doing suspension work this winter so I want to be sure I fix this, and that my new tires do not rub.

Thanks for any input!!
Vince

 

[pgtr]

I would absolutely not consider any low performance passenger tires like, w/ all due respect, the current BGF TAs it has.

I would consider an 'H' rated at a MINIMUM or better yet 'Z' rated all-season performance tire. There are 3 Z rated 225/70s still avail presently (GY, FStone, General) and one or two H rated 225/70s. These are good respectable all-season performers however you may have to special order them from a local tire dealer.

If you would like to get beyond the slim picking of decent performance tires in 15" - I'd skip 16" and go for 17" rims. 16" doesn't offer that much beyond 15" for performance tires. At 17" the selection of good tires expands considerably. I suggest sticking w/ the 8" wide rim and -0.5" offset and ensure the replacement rims clear the calipres of course.

The bottom line is that you can get pretty good all season performance tires in 15" though the overwhelming majority of 15" tires for C3s are hard rubber low performance fare w/ little more than impressive looking sidewalls. Whereas in 17" it's almost impossible to go wrong w/ tire selection.

Anything beyond 17" rims IMHO starts getting to be too flashy for a classic C3 look but that's purely my personal opinion.

I'm a little surprised a 225/70 would rub on a '70 as it's reasonably close dimensionaly to the original F70s and was later the standard tire on C3s w/o any engineering changes to the suspension from '70 AFAIK.

 

[Vinn]

Thanks for the advice. I'll have to check out those high performance 15" tires some more. As far as the rubbing goes, what typically causes that? Old springs?

 

[pgtr]

Sure. More specifically the GY Eagle GS-A, Firestone PV41, General XP2KVR in 225/70 are V rated. The PV41 and maybe the XP2K are considered police tires for what that's worth. Cooper also makes an H rated tire in this size and possibly Kumho last I checked. The Cooper might offer comparable/respectable performance at a more bargain price (and it's still a USofA tire company if that matters). I think any of these are legitimate options to 17" (which you really can't go wrong with either) and light years ahead of the usual low performance hard rubber fare most C3s sport at a modest increase in price. They are also stronger and thus safer tires over compared to the usual suspects to boot and will last plenty long enough.

I should have added that I wouldn't consider anything w/ less than an 'A' temperature rating - again H or above usually assures this.

I don't think springs would cause wear unless we are talking about excessive and low riding perhaps (is it riding excessively low all the time?). WHat about excessive camber? Or worn turn stops allowing the steering to move too far? Beyond that really don't know off hand, haven't messed w/ any suspension stuff in a while and it's layout is not fresh in my mind.

 

[Vinn]

Those are all good points. As you can see in my sig pic the ride height looks fine. I'll check out the other points you suggested - this type of work is new to me.

Thanks again,
Vince

 

[patsnitrovette]

If you go to 17's. a 255/50/17 is 27 inchs tall and a 275/50/17 is 27.8 inchs tall just to give you an idea this is what im running.

 

[pgtr]

Vince,

Your original F70s were 27.0" diameter AND 775RPMs. There are perhaps 4 different 17" tire sizes that should be within about 3% or less of BOTH of those dimensions which is what I would consider.

 

[Bob Chadwick]

Use this tire size calculator to figure out the height for different size tires.

265/50/17 appears to be an almost exact match.

 

[Vinn]

Looks like the best 15" out there's the Goodyear Eagle RS-A, 225/70VR15.

Any experiences with this tire? And while I'm at it, why not open up another can of worms...

Lots of members here have the 255/60/15 size on their cars. Other than looks, does this make a big difference in performance? Thanks for any input.

Vince

 

[pgtr]

Looks like the best 15" out there's the Goodyear Eagle RS-A, 225/70VR15.

Any experiences with this tire? And while I'm at it, why not open up another can of worms...

The Firestone PV41 and General XP2000 VR4 are every bit it's equal. All three are excellent tires. The only reason they are available isn't because of demanding C3 owners but police deptartments - at least for the PV41 and I think the General. W/ few Crown Vics running 15" tires anymore I don't know how long that will last either.

The Cooper Cobra GTH might be able to mix things up too and might be at least worth considering in this size. THere might be one other 'H' rated tire too ... Sumitomo...? Not sure.

Lots of members here have the 255/60/15 size on their cars. Other than looks, does this make a big difference in performance? Thanks for any input.

Lots of potential for sidewall flex on an 8" rim in this size. There is one(1) very good one in this size - the Pirellia Scorpion Zero. It's the OE tire for some Lamborghini SUV I think (don't be put off by the SUV thing - it's a very serious P tire). Kumho may have made one too but I think they dropped theirs recently. Goodyear did make a mid-level performance tire at one point in this size but I think they either dropped it or restricted it to Europe. SO it's just the one Pirelli to the best of my knowledge.

 

[Vinn]

I really like the look of that Goodyear too. If this turns out to be a good tire it may be the way to go... Here's a quick Photoshop of it:

 

[Vinn]

I had trouble finding info on that Firestone tire, pgtr. That Cooper looks good too, although according to the website it's only for up to 7" rim width?

That Pirelli looks like an excellent tire as well.

 

[jwilliams]

Vinn, the goodyear you mentioned is another pursuit tire, just as the firestone pv41, the general xp2000. All of these are going to be better than what you've got. If you want something other than a RBT (round black tire) you really want to look beyond the BFG radial t/a. If you like the look of the car, and aren't after a super aggressive handling sport tire, then get one the 15 inch tires you mentioned. If you're looking to drastically improve handling, you need to go 16 or 17" in order to get a tire with the latest & greatest tech...Your best option in a 15" tire may be the michelin pilot sport XGT H4 P225/70R15. This is a fairly current tire with stiff sidewall and excellent handling characteristics. My dad has a set on his 65 coupe and they work well for weekend cruising and spirited country road driving.

Jay

 

[pgtr]

The PV41 and XP2000 VR4 are probably burried in the government sales section of their respective sites. PV stands for pursuit vehicle.

225/70R15 was the standard tire GM installed on 8" rims back in the mid to late 70s (and before they they installed an even SMALLER tire on 8" rims - the F70 => 215/70R15!). Things have apparently changed at least twice because the Tire and Rim Association has apparently deemed it's too narrow for an 8" rim since then. Taking their cue, most makers just rubber stamp what TRA says and now max the 225/70 at 7.5" or maybe 7". Goodyear still lists 8" on certain models. TireRack pretty much ignores this thing as well and lists either the 225 or 215 for C3s depending on the year.

The Pirelli is every bit as good as it looks but on a 70 like yours a 255 may or may not rub.

 

[pgtr]

Jay I didn't know about the Pilot XGT H4 - thanks. Sounds like there is shaping up to be a reasonable selection of 225/70s w/ H or better after all!

Here's my list acceptable tires...

225/70R15s (all are at least 44psi max)
Goodyear Eagle RS-A 100V 260AA
Firestone PV41 100V 340AA
General XP-2000 V4 100V 320AA
Cooper Cobra GTH 100H 340AA
Sumitomo HTR 200 100H 380AA
Michelin Pilot XGT H4 100H 400AA

255/60R15s
Pirelli Scorpion Zero 102V 340AA
Kumho Ecsta STX 102H 320AA (discontinued?)

There's also some good tires in the 215/70R15 size which matches the F70 dimensionally but the size may be more questionable by modern standards for an 8" rim.

 

[Vinn]

Wow, quite a selection after all. I checked, and that PV41 is buried on Firestone's website.

 

[pgtr]

Indeed!

But dont' forget there's about 40 non-performance tires in C3 sizes all backed by pure marketing BS calling them 'performance' tires heavily crowding this market segment.

And for the guy w/ the 255/60 OE size - selection is still teetering on non-existent for stronger legitimate performance quality tires.

It might be nice if just one tire maker offered a decent tire w/ some sort of 'classic' sidewall treatment like a white stripe or RWL which might look nice on a vintage C3 in 15" but I'm not holding my breath. The C3 15" tire consumer has overwhelmingly chosen very basic non-performance entry level radials by a wide margin.

 

[ernbuild]

Just bought new ones for my 78

I just got rid of my T/A, and fitted new yokohama avids, 255 rear and235 on the front for the same reason ,rubbing on inner guard. Excellent tire though soft ,great performance not so good for longevity. Odd part is I had to bring them in from the states as there not available here in australia. Made a great deal of difference to the handling,Id give them 9 out of10 compared with the old T/As.
Cheers Ernie

 

[jwilliams]

Vinn, the goodyear is a pursuit tire like the firestone and general. Pursuit tires basically have been certified by the manufacturer for pursuit use. It's a liability thing....They will have better wet weather characteristics than some other tires. But their cost on non government sale maybe prohibitive. Don't recall if the goodyear has a white wall. A side note, the current crown vic's have 16" tires/wheels. All the agencies I work with run crown vics. I only occasionally see an older caprice or crown vic on 15's...

Jay

 

[pgtr]

The RSA is not marketed exclusively as a pursuit vehicle tire by any stretch and likely doesn't have it's origins there. It is available in a broader range of sizes, marketed to the general public, widely available and I think it may even be OE on some new cars. Firestone by contrast makes little if any effort to market the PV41 beyond law enforcement circles and only offers it in a 2 sizes (for pursuit vehicles). The General tire seems kinda in between on this - not sure.

The cost difference is about what you would expect between any cheaply manufactured S or T rated tire vs the more expensive construction typically needed to meet H or better. If anything I would think prices may be a little extra high because of the lack of demand among C3 tire buyers for performance tires. But relative to other V speed rated all-season performance tires on other cars/sizes - they are evenly priced and in many cases a downright bargain.

There's also a tremendous degree of variability in 'street' pricing on any given tire - lots of mark up depending on retailer and often lots of room for 'negotiation'.