Current Setup
Wheels: Stock 18”
Front: OEM Bridgestones (225/45/18)
Rear: Goodyear Eagle F1 GS-D3 (245/45/18)

The fronts were replaced by Nissan because of the “feathering issue.” They still have some tread. I just replaced the rears with the Firestone Eagles (EDIT: should be Goodyear Eagles). The car handles a little differently, and I assume that is because of the difference in sidewall rigidity between the Bridgestones and the Eagles. I considering replacing the fronts with Firestone Eagles (EDIT: should be Goodyear Eagles), and the best matching diameter I can get on the fronts when buying the Eagles is 245/40/18.

My Question
Is anyone running these sizes (245/40/18 Front and 245/45/18 Rear) with Goodyear Eagle F1; and if so, how do you rate this arrangement?

I did a search and found several threads where people were considering this setup, but nothing about the results.

 

Good question.

 

^^ Thanks for responding. I’m surprised there are no responses since a search discovers more than one person considering this setup. My guess is that this (245/40/18 Front and 245/45/18 Rear) arrangement on four 18” by 8” wheels is boring.

The obvious answer is installing new wheels (18”x 8.5” front and 18” x 9.5” rear) with new tires (145/40/18 front and 175/40/18 rear). But, I like what is on the stock 2003 Performance model (18”x 8” wheels). And, I would hate spending $3K+ just to replace this.

I absolutely love the Goodyear Eagle F1 GS-D3 I’m running on the rear (245/45/18). They are very quiet (my Z no longer has the tire noise I had when running the OEM Bridgestones on the rear), and the Eagles grip very well in the rain. It’s just a great tire. The only thing I notice is the more flexible sidewall on the Eagle compared to the Bridgestone. It is more apparent since I am running 225/45/18 OEM Bridgestones on the front and 245/45/18 Goodyear Eagle F1 GS-D3 on the rear.

Since my front OEM Bridgestones are going to wear quickly, I plan to replace these with Goodyear Eagle F1 GS-D3’s (and the best diameter I see is choosing the Goodyear in a 245/40/18 for the front). So that leaves me with the same tread width (245 mm) front and rear. And, that is the reason for my question and this thread. My concern is if this arrangement will result in more over-steer than I can manage safely

So far, no other responses.

--Spike

 

The majority of members select a wider tire for the rear to help with oversteering.

 

^^ Thanks for responding. Your input is always valuable and respected.

But I'm asking for experiences when running the same tire width front to rear.
--Spike

 

Goodyear Eagle dummy!!!!! Not Firestones! You are mixing two different tires, no wonder the car handles different. The F1 GS-D3s feel like they have a mooshy sidewall bc of the tread design...though they feel that way, they have TREMENDOUS grip! YOu should never mix tire designs anyway. Were they even the same speed rating? W vs Y??? I don't think they make a matched front size in the F1 GS-D3 so you're S.O.L if you want to get matching fronts. Even if they do, they probably aren't available due to the GY strike....On staggered fitments, the rears are going to wear out twice as fast as the fronts so always replace the rears with the same OE tire and then when the second set wears out, the fronts will be probably ready to go too so then you can replace all four and have a matching set.

 

Tire Rack!!!!

 

Wow! Ok then… Have another drink… I don’t think we are on the same “thread.” My tire wear isn't matching your paradigm (read my post above to see why).

I guess we're into it tonight. Your exclamation key (!) is sticking.

--Spike

 

Are you sure about that?

The Z is notorious for understeer, not oversteer. By increasing the ratio of tire width in the rear you increase the car's tendency to plow. What the majority of performance drivers recommend is increasing the cars front tire contact patch to decrease understeer and give more traction under turn-in and braking.

A 245/40 front and 245/45 rear isn't a bad idea. It will definitely make the car more neutral. Just make sure you know what you're getting in to as many people don't understand how to control a loose RWD car.

 

Thanks for posting a response. You understand. It’s obvious you know what you are talking about. Your wise advice: “It will definitely make the car more neutral. Just make sure you know what you're getting in to as many people don't understand how to control a loose RWD car.”

The information in your response is exactly what I was asking about. I agree that the Z is designed for neutral steering, and putting tires with lesser width on the front compared to the rear introduces some degree of under-steer to make the care drive more safely.

I am planning to put 245/40 Eagles on the front to match the required diameter to the Eagle 245/45/18 I now have on the rear so I don’t encounter interference from the VDC on my Performance Model. Z. And, as you point out; I might experience neutral-steer, and maybe some degree of over-steer when running tires with the same width front-to-rear. I really wanted to hear from someone who has this configuration.
--Spike

 

I believe you and David are on the same page and are in agreement. I think David says that a wider rear tire to front tire ratio results in more under-steer and helps the less experienced driver. David is voicing the same caution you describe: The closer the width of tires front to rear with the Z, the more you will experience neutral/over-steer, and this requires a more experienced driver.

And… Now I’ve managed to “jack” my own thread.
--Spike

 

Ripken Stadium, Aberdeen, MD 11/2006

Come to think of it, I keep sliding into cones with the front of the car. Maybe I need wider front tires also.

 

how can you refute what I said, yeah I was kinda drunk, but the guy called them Firestone Eagles, what a retard. Plus, like I said, you don't mix tires, that's just stupid. I know the Eagle F1 GSD3s are awesome, I've driven them, I went to the Bondarant Performance driving school (won a sales contest at tire rack) they grip great, but what I was trying to say is that you shouldn't have gotten the Eagles for the rear bc I don't think they make a front fitment when its time for the fronts to match up. Duh.

 

I do not see any mention anywhere on this thread that references “Firestone Eagles” so I don’t know what you are talking about. If you see this “mis-reference,” please copy it as a Quote and post it here.

To match front tire diameter on the Z, you install Goodyear Eagle F1 GS-D3 (245/40/18). That is nearly an identical circumference match to the Z’s OEM 225/45/18 tire. My question is asking about experiences on these two different tire installs running with the stock Z rear tire size (245/45/18). I’m mostly interested in hearing about potential over-steer with this arrangement.
------
EDIT: You're right it should be Goodyear Eagles

 

Just thought I'd help out...

 

oops...

Now I've forgotten the original question...
Rats... ruined my own thread.

 

I ran those exact sizes/tires on my G35 18's. I don't think oversteer will be a problem especially if you are still on the stock suspension. If you are running an aggressive sway bar setting, you might want to either stiffen the front or soften the rear. Just take it easy until you know the handling characteristics but an extra 20 mm in the front really won't make THAT big of a difference.

 

Thanks for the reply. I appreciate your response. Actual experience provides the most valuable information.

One other question:
Do you notice any “wandering” or “bump” steer at highway speed when running the same front and rear tire widths (245’s on the front with 245’s on the rear)?

(I’m running on a non-modified suspension and OEM 18”x 8” wheels.)
--Spike
_________________
EDIT: For spelling error ("bumb" changed to "bump" steer)