Tire sizes

Hi,

I currently run 185/60/13. It feels slightly over tired ( no pun intended).

Will returning to the stock 165/70/13 make the car feel more nimble and light?

On my previous '75 I actually ran 145's and loved the steering!

Car's an euro spec '80, lowered 30mm on custom springs and red konis.

Perhaps do a string alignment first before changing tires?

It definately should not feel over tired with 185/60's - If that's the case then I'd delve into the alignment settings to see if things are set where they should be.

You're not driving it hard enough!! LOL!

What brand and model of tire are you using?

I just put on a new set of 185/60/13 Yokohama A539 and they are amazing!!


Mind you, I drive it like as if was a rental...

I think you might need better tires, not a different tire size. I felt a difference between 165/70/13 and 186/60/13s the first time I changed tire sizes. Then I got different 185/60/13s, I think I got the Yokohamas and the steering response was much better than the previous 185/60 13s, more like the 165/70/13s felt. I now run Toyo Proxy 195/50/15s and they feel a little bit less responsive or nimble than the 165/70/13s felt, although the trade-off is you get incredible amounts of grip instead. I also have a Racecar set up with 225/45/15 Hoosier slicks and the steering response feels almost too quick to drive on the street. My opinion is that although width of the tire does change the feel of the steering, the construction of the tire's sidewall has a lot to do with it as well. if you want really good grip and steering response in a 185/60/13, I would suggest the Toyo Proxy 888s. They are a very soft compound though so they don't last as long as harder tires and they aren't great for wet conditions either.

Gruf, whatever you do, just DON'T LEAP BACKWARDS...

Stay away from ANY 70-series tire and go with 60 or 50s or even 45s on 15 inch rims. For all the reasons others have stated PLUS better handling and braking.

Black-Tooth said:

Stay away from ANY 70-series tire and go with 60 or 50s or even 45s on 15 inch rims. For all the reasons others have stated PLUS better handling and braking.

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Tell me again why one should stay away from 70 series tires.

Ha... I dunno if yur messing with me or not...

So I'll just add one more comment to the others above and say two words: Contact Patch.

If you are serious I can go into more detail... I mean you can purchase a 70's series tire, and they are plentiful and inexpensive... but the performance of a 60 series is so much better and that is not just an opinion.

Not messing

Black-Tooth said:

So I'll just add one more comment to the others above and say two words: Contact Patch.

If you are serious I can go into more detail... I mean you can purchase a 70's series tire, and they are plentiful and inexpensive... but the performance of a 60 series is so much better and that is not just an opinion.

Click to expand...

Bigger foot print and....?

In Tony we Trust......

I have 175/70R13 on the original tron rims on my 86 and 165/70 R13's on the original steel rims of my 79, thats what was on them when I got the cars. They are all in good shape, but I wanted to change the rims out to dress up the cars (keeping original rims if I every want to put it back to original).

I did my research and took the advice of Tony and others and decided to go with 60's for my new rims for both cars. I put the 185/60 R 13s on the the rears and 175/60 R 13 on the fronts and it made a world of difference. You don't need to go smaller on the fronts, I just did it cause I wanted to, it evened out the look of the car as the front sits a little higher then the rear. If I could have found 205/50 or 60's for the rear I would have, but those are hard to come by. I found Achillies 122 for cheap, they are not a bad tire, good flat tread and on a car this light they should last along time.

Still working on the rims for the 86 but on the 79 with Cheviot Gold rims it rides and handles alot better then it did with the 70 Sussex's it had on the old rims.

PW

Pros and cons...

A wider tires doesn't provide a larger contact patch, it provides a wider one. The overall area of the tire's contact will be very similar, the weight of the car is spread over a similar area in terms of square inches (or centimeters) but the patch will be wider using a wider tire. If the contact patch is larger it may be less effective per square inch, since the weight is distributed over a larger area. I'm simplifying but I think it's something to consider.

Wider tires make for more stable feeling cornering, but also can make the steering less nimble-feeling and cause road imperfections like truck traffic troughs to affect the direction the car will self-steer in.

With wider tires comes thinner sidewalls and less comfort if you use a larger diameter wheel. If you use the same diameter wheel and go wider the aspect ratio will be different, but the overall sidewall height should be similar to keep the same rolling diameter. If you change the rolling diameter, the speedometer will be affected as will mileage and overall performance. Smaller rolling diameter will result in quicker starts but less power at high speed, and an optimistic speedo.

Remember the X suspension was designed for narrow tires.

Sorry then... I have just written this...

so many times before and when you said, "tell me again..." I thought you were poking me with regard to how many times I have written it! That coulda been in fun or with sarcasm so I thought I would just be brief. HA!

Sooooo... Everything Paul wrote and more... besides the fit and APPEARANCE.

First, the aesthetics before I speak to the tires...

I hated the "look" of my nose-high and DART appearance of our cars that came about when FIAT was forced to meet NA bumper-height requirements. It also 'statically' placed MORE weight on the rear of the car which it simply did not need at 66 horsepower. So I cut the springs and lowered it 2 inches at the front bumper in order for the rocker panel to be about 1/4 inch lower as measured behind the front tire... as compared to the measurement in front of the rear wheel... giving the car what I consider a proper WEDGE appearance.

As to the tires...

With the stock 165/70x13s and then later with the 175/70x13s, I had terrible front end LOCK-UPS on turns, as well as when going straight. The 175's also rubbed a bit on full lock when backing... just on the LF tire! Strange huh... Anyway, if it rained the problems were ten times worse and was as if I was on ICE trying to STOP and STEER to avoid another car or mountain of cliff! The nose- The high and the small footprint did not help this situation.

My first experiment to correct this was to vary tire pressure and I got down to about 16 pounds up front as compared to about 32 in the rear to "balance" the lock up while BRAKING. STEERING was a bit better but now the sidewalls were just too floppy due to their size and construction. This was better but geez... 16 pounds of air up front?

My next experiment was running 185/60s all around and man what a difference! The wider width to sidewall height greatly improved traction in all arenas. Then I lowered the front as described earlier which virtually eliminated the problems altogether.

I next went back to my hot-rodding routes and installed a huge "rubber rake" with 175/50s up front and 205/60s in the rear (Yes, you read that right...) This really looked "Kool" and performed very well also, but it was just too much of a "difference" in sizes for this car... as a Sports Car and not a Hot Rod.

(One such car that did LOOK right was when Ricardo here installed 175/50s up front and 215/50s in the rear on 14 x 6 Penta-Star type wheels. It SLAMMED the car down and increased the overall width and I don't recall that he even messed with the springs. It looked and I would think had performed great. I have underlined the KEY points in the last two paragraphs just to emphasize they are NOT typos.)

Fifty series tires nowadays run about the cost of all four 60 series tires just for ONE.

I guess I could go on for hours... but the bottom line for ME these days are 175/60s up front and 205/60s in the rear for the rake and comfort and performance and looks that I need and want. A milder rake would be to run a 175/60 up front and a 185/60 in the rear. 185/60s all around makes the MOST sense theoretically for rotation purposes... but with a correct alignment I never found the need to rotate them and it was no longer my daily driver...

Lastly... if you live outside of CA or can order them from another state... 175/60s and 185/60s from many companies are relatively inexpensive and perform well. The Achilles tires can be had for $150 bucks for ALL four in these sizes or combos, delivered!

These Achilles have been proven to be a Godsend for most of us and perform well with NO shimmy-ing complaints due to sloppy construction. We have NO long-term wear reports as yet as they are just to new to us...

On the the other hand, the Federal brand tires have proven to us so far to have a 50% reject rating... and Nexen's just seem to be NLA like the Sumitumo's that many of us used for years.

There might be more but I think I'm developing carpel-tunnel-syndrome from writing this post alone. If ya have anymore questions just ask. HTH

p.s. If you are considering a larger WHEEL, there are many Italian 14 inchers that look RIGHT but 14 inch tires are difficult to find and pricey. Fifteen inchers would be the best bet for MASSIVE tire selections and many of our venders have package deals with a wide selection of performance wheels in a wide selection of colors as well. This is a topic that would require another CHAPTER here...

OEM 165/70 13 Recommendations?

What brand and model tire does the forum recommend for OEM 165/70 13?

I appreciate everyone's comments on larger size. However, I want to keep the car stock. And Pirelli P3 are no longer manufactured.

Thoughts? Comments?

+1 for the Achilles 185/60, I've been running them on all four corners since last fall, snow, ice, water, curves as hard and fast as I dare, heavy braking, all good, quiet too.

Thanks Tony. No sarcasm was intended I just wanted to hear what you had to say as well as any input from any of you other guys and gals. I started running 175/70 tires back in 1976 to replace the stock 80 series that were on my first Fiat. It was a 75 128 sedan. I have had no major rubbing issues with the 175/70 and they have served reliably over the years. One of the first things I did when I got a Fiat was adjust (lower) the ride height. My 84 X is lowered and the tires fit nicely in the wells. I would go a taller tire if I could as my car has a good bit of low end torque and could handle a slightly larger diameter which would also add a tiny bit more top end. I hope to read more input about the fitment of tires and sizes and rims.

Now this, is "over tired"



Sorry, thats all I got...

Pictures of your "rubber rake"?

Hi Tony,

My first post on X-Web. Your post was timely as I am debating wheel fitments in my head. I was thinking of the 175/50/13 front / 205/60/13 rear fitment that you have had experience with. The "rubber rake" you called it! For wheels I would be working with 7" fronts and 8" rears. Tires would be Yokohama A048's (which I'd have to import as they are not distributed domestically).

My inspiration was the Lancia Stratos Zero concept car (as well as limited tire choices!), but not sure it will translate well to the X1/9.

By chance do you have any pictures of that fitment?

Thanks!

Chandler... welcome to this site and L.A.

I'm north of downtown by about 45 miles and I know you might have some issues with giving out personal information. Hopefully we can prove ourselves to be honest and trustworthy people.

There are about 50 of us from San Diego to Santa Clarita with a smattering of folks in between going as far east as Palm Springs and as far west as Torrance. We get together infrequently but about 3 or 4 times a year with groups from 2 to 10 to 20.

I have a foto here of Tommy's car that has a stock suspension and some new tires he just got and mounted on 13 x 5.5J wheels with the aforementioned sizes. I think this shot shows it well.



Click on foto to expand it. Now note, the rear tires do not appear that big in person and the car is pointing downhill a bit... but its a good example. I'm afraid I do not have any late fotos of my car but here is one from about 10 years ago.



I've lowered the front end one coil and massaged it for an overall drop of 2 inches at the bumper.

Details on request.

BUT...

7 and 8 inch wide rims MAY impose a problem with clearance to the springs or struts and the inner fender well. Your car should come with one small spacer that can be removed or others added with longer studs.

BUT... you really need to use a tire calculator or purchase a tire fitment tool to be sure.

Even with that... 13 inch tires are almost unobtainable and if you are going with aftermarket wheels, step up to 15s as they give you a plethora of choices... and they look really good!

HTH... write or call if you like... 661-296-7277

Here is a picture of Tony's big'n'littles.

From Tony's SoCal gathering way back when. I think Sister Margaret took this one:


and another, same day. Now I know I didn't take it since I am in the picture.

I didn't have those... thanks Jim... and BTW...

The bricks behind the wheels were because the trans was out of the car and I didn't trust the e-brake on the hill. Thanks for the memories... that was 9 years ago!

Black-Tooth said:

The bricks behind the wheels were because the trans was out of the car and I didn't trust the e-brake on the hill. Thanks for the memories... that was 9 years ago!

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It is called an Arkansas emergency brake except instead of brick we use natural rocks. Thus the state slogan of "the natural state." There is no need to carry one with you as they are quite abundant here.