14inch wheels v 16inch on an early 308.

Maybe a little. The 308 is a truck at speeds under perhaps 15 mph and certainly under 5 mph to anyone who grew up on power steering. I certainly did not so it is normal to me.

Remember, it is the width, well over the height that determines how hard the steering wheel is to turn at very low/no speeds.


And the 16's look much better iMO.

 

The Spare Parts Catalogues for Europe (and Australia)
of December 1975 (???/75) and September 1976 (129/76) for 308 GTB vetroresina
and of July 1977 (145/77) for steel 308 GTB & GTS
list the following standard and optional wheels:
Dec 75 - standard 6.5 x 14, option 7.5 x 14
Sept 76 - standard 6.5 x 14, option 7.5 x 14
July 77 - standard 6.5 x 14, options 7.5 x 14 and 7x16 front with 8x16 rear.

BTW the big front spoiler option is listed in the July 77 Spare Parts Catalogue but not in the Dec 75 nor Sept 76 issues.

 

Anything on mirror options?

 

Are you asking wrt your GTS qv?

 

Regarding new Michelin XWXs, could someone comment on my (mis?)understanding that while the design remains unchanged and classic, the construction, compounds, etc, are modern. The tire is a high speed/performance tire with the limitations of its classic design only.

I understand it will never perform like a modern design, but it is not the same tire as the original XWX, right?

Ciao!

Hannibal

 

It certainly is a different tyre in compound and construction.

I was wrong the other day about the TWI. It's 100! Very soft and grippy.

 

The question came up in regards to 82 GTS

 

The original Michelin XWX was released in late 1968 and was of the following construction:

Original version, 1968 to about 1982
2 steel tread plies
1 nylon sidewall ply
TWI Unknown but my guess is around 150.
Thick sidewall.
V Rating, 240 km/h


Updated version post 1983 - Current
2 steel, 2 polyester and 1 polyamide tread plies
2 polyester sidewall plies.
TWI 100
Thin sidewall.
V Rating, 240 km/h however this was changed to "W" (270 km/h) sometime in the 1990s but the "VR" script was kept on the sidewall to keep the purists happy. These later "W" rated tyres can be identified by the "W" following the load index rating of 89 stamped inside a circle on the sidewall.

With this new construction post 1983, it seems about the same time the compound was softened to a tread wear index of 100. Additionally, the sidewall thickness was reduced by quite some amount and this accounts for the weight difference between the old and the new.

I have found with this updated XWX that due to the thinner sidewall, an increase in tyre pressures front and rear over what's originally suggested to about 33psi front and 36psi rear works well.

From 1968 the XWX was manufactured by Michelin in France, Germany, Great Britain and Spain, perhaps some others. In the late 1990s Michelin wound production down in all factories except for France. Around 2012, the entire Michelin classic tyre manufacturing division was moved to Serbia with a corresponding (Albeit slight) decrease in price.

The steering is slightly easier with an XWX over a 205/55-16 for the reason that the XWX is measured as a 205 not across the tread, but front sidewall to sidewall so the actual tread blocks are around 180mm across. A 205/55-16 is about an extra 2cm wider in effective width.

Speaking from testing many tyres on 308s, I strongly suggest you try to secure a tyre that features a TWI of around a maximum of 200 if you are going with the 16" option. The last time I checked, only two tyres fitted this description, the Continental Sport Contact N1 and Bridgestone S-02A (N2). the "N" designation means these are Porsche fitments and therefore feature the lower TWI.

The problem with most tyre recommendations is that users report that whatever the new tyre fitted is better than the old set. That's because they're coming from using worn and/or aged tyres so of course the new ones will feel better.

I have also tried the Vredstein and although it was the only other "V" rated tyre in the 205/70-14 size it did not have the grip of the XWX in the dry but I believed it featured superior wet weather performance. This needs further investigation as I have no data to back up the above claim.

No tyre whether fitted or not should be used if older than 7 years.

 

As suggested, I would study the thread and subsequent chatter here:

http://www.ferrarichat.com/forum/308-328/389563-308-gtb-vetroresina-24.html

Additionally, the parts manuals get a resounding thumbs up from anyone wishing to study the official introduction of options and changes, they are available on line.

Just to set some homework for you, there is no Euro 4 pipe exhaust, that exhaust is only for USA, Japanese and Australian versions. All other carburettor 308s up to the introduction of the injection models feature a single pipe exhaust.

 

I ran the original TRX and now have the 16" Comps. I much prefer the look, feel and performance of the 16. The original wheels/tires will always stay with the car but, I'd never run them again.

 

Thanks, Carl888. Great rundown on the XWX.

Has anyone run the BF Goodrich Radial T/A in 215/70R14 on their 14" wheels? It's not speed rated like the XWX, but, apparently can be run back wall out so no white letters showing. I searched before writing this and only found this option suggested a few years ago. No reports anywhere. For $500 for a set of four, I may just give it a whirl.

Ciao!

 

I have zero experience with that tyre on a 308 but I fitted a set to a Pantera some years back and thought they were awful. Very soft in the sidewall that made the turn in vague and poor grip. Might make an OK tyre on a heavy hot rod with a large lump of street iron up front but on a lighter car I didn't think they worked. They have a VERY high TWI BTW, the thing you should stay away from on a 308. It's also the wrong size for the 308. Avoid. Just my opinion.

 

Good enough logic for me. Thank you!

Ciao!

Hannibal

 

Let me try and put it to you another way....if the BF-G tyres were $400 each, as was any other 14" 205 tyre, then everyone that ran 14" wheels would use an XWX without question. The fact is the 14" tyres discussion is actually about price, that's all. The problem is that the XWX is the correct tyre, in size, in speed rating and in grip (There's that low TWI again). It's just expensive.

Let's look at the cost of an XWX over the life of the tyre. Assume you do 25,000 miles on a set in 7 years. Your tyres would have cost about $1,600. But in that time, your car would have consumed a minor service every year at say $800 per year plus a belt change and at least one valve adjustment. Lets call that another $5,000. Add insurance, registration and fuel for that period, say 1,250 gallons and you can see the tyres is only about 10% to 15% of the running costs of the car, assuming nothing breaks or needs refreshment as we are just speaking about maintenance. Even if you managed to get the BF Gs for free the XWXs still remain a nominal cost in the overall running expenses.

 

Again, thanks to all for posting. This is a really great discussion for those considering keeping or going back to 14"s. Carl888's point on on the cost over time as a percentage of total operating cost is very pertinent. I just bought 14" wheels and since I did it for originality and for the vintage appearance, I might as well shod them with the correct rubber and get the best performance available for that wheel.

Ciao!

 

Thanks a lot, Carl! Great knowledge.
Are you saying the Ansa 4 pipe exhaust was never available as an option by Ferrari for European carb 308 GTB & GTS?
So the dealers in Europe just fitted exhausts from the 308 GT4 up to 1980 (slightly triangular cross section of tge muffler) and later the owners mounted those from the 308 GTBi & GTSi (oval muffler)?
How does the exhaust for the US carb 308 GTB & GTS compare to these European 4 pipe exhausts?

 

I think 14" look bad ass......but Im biased
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The car was designed around them.

 

yes 100%

 

I like both and always have.

 

How liberal of you.

 

14s baby!!!!!
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I think 14s give the car a more classic look and 16s a more modern look.
Unfortunately on my early gtb a previous owner decided to up grade front brakes
with larger brembo discs and calipers so 14s are not even an option,though if I come
across a set I will buy them for the sake of originality.
Paul

 

308 looks great with every rim size, but i think the 16" is more aggressive and makes the car looks better.

As the 16" are cheaper and by far better performing (due to the actual modern tyres you can put on it), i think the 14" aren't a good choice, unless the car cannot wear the 16" or you prefer the old look style. The TRX are midway and as expensive as the 14".

I think 14" well matches the slim front spoiler and the 16" better matches the big front spoiler. TRX are good for both.

ciao