Direzza ZIII vs. Yoko AO52

[kger]

Well I've read just about every tire post out here, but there's very little clear feedback on this comparison (or just feedback on either tire for my use case), so, help me out.

Use Case: 911SC with performance focused upgrades on 16x7/8 fuchs. Some DE and track time but mostly driven hard for fun 5k miles a year in fair N. CA weather. I want to try some stickier rubber. Currently running old Direzza DZ102s in OEM 205/55 and 225/50.

Question 1: Does anyone have feedback on the AO52's or Direzza ZIII's for this type of use? How about a direct comparison ether first of second hand?

Question 2: The car is at euro height w/ rolled fenders, should I go up to 225/50 and 245/45s? They are available in both tires.

Thanks!

[Bill Verburg]

Originally Posted by kger

Well I've read just about every tire post out here, but there's very little clear feedback on this comparison (or just feedback on either tire for my use case), so, help me out.

Use Case: 911SC with performance focused upgrades on 16x7/8 fuchs. Some DE and track time but mostly driven hard for fun 5k miles a year in fair N. CA weather. I want to try some stickier rubber. Currently running old Direzza DZ102s in OEM 205/55 and 225/50.

Question 1: Does anyone have feedback on the AO52's or Direzza ZIII's for this type of use? How about a direct comparison ether first of second hand?

Question 2: The car is at euro height w/ rolled fenders, should I go up to 225/50 and 245/45s? They are available in both tires.

Thanks!

For performance A052s

for sizes on7&8 x16 205/50 and 225/45 x16

Lower the car some more

[rikaro]

Both different type of tires. The A052 is the one to go for if you're looking for dry grip performance. Sidewalls are much stiffer than DZ102

I'm running 225/245 with euro height and rolled fronts. Go for it.

[Bill Verburg]

Here's a comparison of 205/50 & 225/45 w/ 225/50 & 245/45 all on the same 7 & 8x16 Fuchs


What doesn't show here is the loss of grip from wider tires on narrower wheels vs narrower tires on wider wheels

What does show is the new loss of ~27lb-ft of torque to driver the bigger tires and the lack of room at the front lips, it can be done but there will be a bit of work and compromise involved

[sknandigam]

Very happy with ZIII on my SC, 235/40-17 and 255/40-17. They sacrifice some ultimate dry grip to A052 but wear better/last longer. A052 tend to overheat and get greasy on track.

[Driven97]

The Hankook RS4 is another option your current sizes. A little more durable / consistent for DE use than either of the listed choices.

Any of the choices will blow the DZ102 out of the water.

[BER]

Originally Posted by Bill Verburg

For performance A052s

for sizes on7&8 x16 205/50 and 225/45 x16

Lower the car some more

+1 what Bill says!

Only difference on my car is the size of rear wheels...9x16 with the 245/45x16 tires.

For the price, I find it hard to beat the stickiness of the Yoko's. Try a set...you will not be disappointed.

[kger]

Originally Posted by Bill Verburg

What doesn't show here is the loss of grip from wider tires on narrower wheels vs narrower tires on wider wheels

What does show is the new loss of ~27lb-ft of torque to driver the bigger tires and the lack of room at the front lips, it can be done but there will be a bit of work and compromise involved

Thank you Bill, this is fantastic. To confirm, you do mean that there is more grip with the wider cross sections and less with the narrower, assuming the same rim set, right?

Giving up 27lb-ft torque for some extra lateral Gs in a mostly street car seems insane. I think I'll be sticking with the OEM sizing. They feel and look right to me now anyway. Plus max grip isn't usually the issue with this car, it's more power restricted than anything.

[kger]

Originally Posted by rikaro

Both different type of tires. The A052 is the one to go for if you're looking for dry grip performance. Sidewalls are much stiffer than DZ102

I'm running 225/245 with euro height and rolled fronts. Go for it.

Thanks for weighing in. A few follow up questions for you on the AO52s:

-How do you find the road noise?
-How do you find they wear (street vs. track, etc)?
-Do you have any experience with the ZIII's to compare either yourself of secondhand?
-Do you notice this ~27lb-ft torque loss with the larger sizes? If so, is the handling/grip benefit worth the trade off for you?

Thanks!!

[Bill Verburg]

Originally Posted by kger

Thank you Bill, this is fantastic. To confirm, you do mean that there is more grip with the wider cross sections and less with the narrower, assuming the same rim set, right?

Giving up 27lb-ft torque for some extra lateral Gs in a mostly street car seems insane. I think I'll be sticking with the OEM sizing. They feel and look right to me now anyway. Plus max grip isn't usually the issue with this car, it's more power restricted than anything.

I can't say w/o doing blind back to back tests that one tire is better than another but it is a fact that the wheel width / tire width ratio favors the highest possible ratio

ie the wider the wheel on the same tire the higher the ratio the better performance and less comfort will be derived from the tire

225/45 on an 8 ratio is 1.00, on an 8.5 it is 1.063
245/45 on an 8 is .952 on 9 it is 1.0714

so comparing 225/45 on 8 to 245/45 on 8 the nod goes to 225/45, on a 9 the grip level goes up but the torque cost also goes up, each application needs to be evaluated to see if the trade off is worth it.

the gearing cost and the mass cost go into the net torque needed to drive the wheel/tire assembly, by the far the gearing cost which is proportional to the tire loaded height is the more significant factor

the more hp and torque your motor has the more you can afford to use bigger tires, which can but don't always provide more grip

when I had a stock Carrera 3 liter motor in my '76 7 & 8 205/50 and 225//50 x15 was by far the best performing combination, I went down the rabbit hole and went 8 & 9 x16 225/45 and 245/45 tires and for some tracks it was better and for others not so much and for street not at all needed, w/ a blueprinted 3.8 235/45 & 275/40 on 8 & 9.5 x17 was too much tires for most purposes, w/ a cammed 993 3.6, 8 & 9.5 225/45 and 255/40 x17 is a sweet spot

transmission gearing can also be a factor, but most use stock 915s or g50s so I don't usually mention that

[Driven97]

Originally Posted by kger

Thanks for weighing in. A few follow up questions for you on the AO52s:

-How do you find the road noise?
-How do you find they wear (street vs. track, etc)?
-Do you have any experience with the ZIII's to compare either yourself of secondhand?
-Do you notice this ~27lb-ft torque loss with the larger sizes? If so, is the handling/grip benefit worth the trade off for you?

Thanks!!

I have a set of A052. I have not run the ZIII, but have run the ZII, Rival S, and RE-71R on my 911.

Th A052 is relatively quiet. The RE71 is obnoxiously loud. Also nothing has as stiff of a sidewall as the RE71, but the A052 rides well for the tire category.
A052 wear is probably the worst of all current 200tw tires. They like camber, too, so hope you've got some.
Again, haven't run the ZIII. But I can say the A052 works well right from cold. Most people report extreme ability to put down power, which isn't typically an issue on 911s.
The torque advantage from smaller diameter tires is definitely noticeable. But note you're changing gearing to get it. Effects highway rpm and also may put you in a different gear in certain places on a track.

When I ran the super short 245/40-15 Rival S I used to carry them in the back seat rather than drive on the highway with them. 2nd gear had some real punch though.

[IROC]

Originally Posted by Driven97

The Hankook RS4 is another option your current sizes. A little more durable / consistent for DE use than either of the listed choices.

Another data point for the RS4s...we actually race on these tires (ChampCar Endurance Series - E36 BMW) and they are very good. Way more abuse than street/DE and not only do they hold up well, they are amazingly sticky for a "street" tire. We run races anywhere from 7 to 14 hours in length and we get multiple races out of a set. Incredible.

[Bill Verburg]

Originally Posted by Driven97

I have a set of A052. I have not run the ZIII, but have run the ZII, Rival S, and RE-71R on my 911.

Th A052 is relatively quiet. The RE71 is obnoxiously loud. Also nothing has as stiff of a sidewall as the RE71, but the A052 rides well for the tire category.
A052 wear is probably the worst of all current 200tw tires. They like camber, too, so hope you've got some.
Again, haven't run the ZIII. But I can say the A052 works well right from cold. Most people report extreme ability to put down power, which isn't typically an issue on 911s.
The torque advantage from smaller diameter tires is definitely noticeable. But note you're changing gearing to get it. Effects highway rpm and also may put you in a different gear in certain places on a track.

When I ran the super short 245/40-15 Rival S I used to carry them in the back seat rather than drive on the highway with them. 2nd gear had some real punch though.

I never noticed the RE71s to be loud but then I'm used to NT01s which also howl a lot, similar to the 888s, All of these can also be used on the street

I'm also biased by the available sizes , only the 888s, DZiii and 052 are available in 205/50 & 225/45

[Tipo R]

Originally Posted by Bill Verburg

I never noticed the RE71s to be loud but then I'm used to NT01s which also howl a lot, similar to the 888s, All of these can also be used on the street

I'm also biased by the available sizes , only the 888s, DZiii and 052 are available in 205/50 & 225/45

How was your experience with the 225/45 15 (23” diameter just like the 205/50) for the rears at highway speeds? Engine speed too high? Aesthetically, did those look proportionally too small without lowering suspension.

Similar to OP, I’m considering A052s (on 7/8 x15s) for summer use on stock 3.2.

[Bill Verburg]

Originally Posted by Tipo R

How was your experience with the 225/45 15 (23” diameter just like the 205/50) for the rears at highway speeds? Engine speed too high? Aesthetically, did those look proportionally too small without lowering suspension.

Similar to OP, I’m considering A052s (on 7/8 x15s) for summer use on stock 3.2.

certainly the freeway cruise rpm is raised by the shorter tires, as for appearance my car has always been extremely low, appearance has always been outstanding judging by the frequent positive comments and offers out of the blue to buy it

low cars are not for everyone, I've never had an issue w/ the C3 but my 993 low and projecting front spoiler is, the only issue the 911 has ever had is scraping the exhaust tips

[Bill Verburg]

I just looked up the differences between a 225/45 x16 and a 225/50 x16 on an '81 US SC
these are speeds at a set rpm in 5th

225/50
2000 47
3000 71
4000 94
5000 119
6000 141

225/45
2000 46
3000 69
4000 91
5000 114
6000 137

[Tipo R]

Thanks! RPM delta doesn’t seem significant on 16” wheels. I’d vote for the smaller dia 225/45 AO52 on next set for the 16” Fuchs.

Would you say your experience with height and engine speed be similar on 15” wheels? I’m asking as you had previously written, “...when I had a stock Carrera 3 liter motor in my '76 7 & 8 205/50 and 225//50 x15 was by far the best performing combination...”. I also have the correct date coded 7/8 x 15” Fuchs for my 84 3.2; hence I asked about the 15”.

[Bill Verburg]

Originally Posted by Tipo R

Thanks! RPM delta doesn’t seem significant on 16” wheels. I’d vote for the smaller dia 225/45 AO52 on next set for the 16” Fuchs.

Would you say your experience with height and engine speed be similar on 15” wheels? I’m asking as you had previously written, “...when I had a stock Carrera 3 liter motor in my '76 7 & 8 205/50 and 225//50 x15 was by far the best performing combination...”. I also have the correct date coded 7/8 x 15” Fuchs for my 84 3.2; hence I asked about the 15”.

The op asked about tires for 7 & 8 x16s,

15s is a whole lot different


here's a survey of what fits an SC/Carrera

you really want to keep the tire OD under 25" if possible unless you have a much more potent motor or have regeared the trans, Ho short can be debated ad infinitem, each owner will have to make their own decision based on their needs and perspective

The green areas are using standard available Fuchs, the yellow areas are custom o/s aftermarkets

[Tipo R]

Thank you, Bill.

[kger]

Thanks everyone for your responses.

The Direzzas were out of stock in my sizes everywhere so I ended up going with the A052's. They get installed next week and I have a track day two weeks later so I'll report back here on both street and track impressions.