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275/40, 285/35, or 295/40 Hankook RS4 on an 18x10 Apex ET42

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Duane Black

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greetings track connoisseurs,

I'm good on tires for now, but can never have enough spares, right?

I've run 285/35/18 on 10" wheels for 2 sets now. The gearing change going yo hankook over bridgestonr (285/30/18) made be faster despite less grip due to the straightaway speed my v6 could muster... 122 on straighys was all 4th had, and you'd just hit limiters at the end of the back straight at vir. With 285/35, im at 130ish with the same rev limiter. I know monster tires forever arent the way to go... but i still wonder... could i be faster yet eith a 40 profile? The correct answer is probablu gear, but alas...

Is a 295/40 on 10" wheels too much? Is 275/40 safer? I dont mind running a 3-6mm spacer. Ive got -2.5 camber on stock style struts. The 275/40 set would save me a couple hundred bucks a set, but would i constantly wish I had sprung for 295?

I'm also aware wheel width can affecr tire contact.... so is the contaxt patch a negligible difference here anyway?

If it matters, a 295 is 3 more lbs than a 275 and 4 more lbs than a 285.
 
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Philly Metro Area
Watching since I'm considering going to the 295/40-18 RS-4s on 18x10 wheels. I am currently running square 285/40-18 (27") They are perfect on the 18x10s. The 295s may be a tad pinched but not too bad.

Apex's wheel fitment guide states 295/40-18 are ok with -2 camber and 12mm spacers. I have ET45 wheels now and my 285s are 11.4" wide and don't need a spacer but use a 3mm just to be on the safe side. An ET42 should provide another 3mm clearance on top of that. I think 5mm is the max recommended for stock studs.


It may depend on the actual tire. For example the Hankook RS-4s are listed as being wider (12.2") than the Falken RT615K+ (11.8"). Nitto NT05's are 11.85" wide. All were measured on 10.5" wide wheels. The 0.4" difference between my 285 and two of the 295 tires equates to 10mm and therefore 5mm on each side. With ET42 wheels a 5mm should be enough. The Hankooks are supposedly another 10mm wider still. That may require a 10-12mm spacer and new studs.

Other than mine is a V8, I guess I am in a similar situation as you. I can get to just above 140 at Pocono in 4th on my 6R80 and 3.55 gear by 7600 soft redline. My limiter is at 7700. If I go to a shorter tire then I'd have to use overdrive 5th which I want to avoid.

I went from the stock 3.15s to the 3.55 to avoid having to downshift into 2nd as often as a I had to. Except for the tightest corners I'm in 3rd except for the straights.

NOTE: Edited to change ET43 to ET42 and 2mm to 3mm
 
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Duane Black

Curbs go brrrppp
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Their guide is interestingly referencing the et40. Im running an et42, 285 tires, which they claim needs a spacer, and I've no issues... could hook a finger, albeit barely, between the tire and the strut. No spacer either!
 
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I went with the Falken Azenis RT615K+ in 295/40-18 on older ET43 EC-7 18x10 wheels. No rubbing with just a 3mm spacer. I also have the Roush steering rack limiter that I was also using with my 285s. I only have one HPDE day on them on real hot day at Pocono (SE Option 1). Still dialing in my tire pressures. I kept reducing the pressures between 20 minute sessions and got them down to 36 psi hot. But I ran out of time so I'm wondering if there are any benefits by dropping to 35 or 34 hot.
 
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I went with the Falken Azenis RT615K+ in 295/40-18 on older ET43 EC-7 18x10 wheels. No rubbing with just a 3mm spacer. I also have the Roush steering rack limiter that I was also using with my 285s. I only have one HPDE day on them on real hot day at Pocono (SE Option 1). Still dialing in my tire pressures. I kept reducing the pressures between 20 minute sessions and got them down to 36 psi hot. But I ran out of time so I'm wondering if there are any benefits by dropping to 35 or 34 hot.
Any way that you can post pictures of how these fit? Just picked up a set of 18x10 and I am in the same boat wondering if I should go with 295/40 or stay with 35’s.
 

Bill Pemberton

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( Cyclyn3.7 ) Considering the speeds you will get on the tracks near you ( Hastings, Topeka, Cresson, ,Hallett ) I would go with a 35 as gearing is more important for you and with the V6 you are not going to be approaching high enough speeds that it will benefit. More important coming out of some of the tight corners to have a bit more grunt.
 
( Cyclyn3.7 ) Considering the speeds you will get on the tracks near you ( Hastings, Topeka, Cresson, ,Hallett ) I would go with a 35 as gearing is more important for you and with the V6 you are not going to be approaching high enough speeds that it will benefit. More important coming out of some of the tight corners to have a bit more grunt.
Thanks Bill! Would it make a difference being that I have a 3.73 gear ratio? I realize that only goes shorter and essentially, I’m at a 3.98 gear right now with some 285/35 on these 18x10 SVE Drifts I picked up. They’re some cheap all seasons so that’s why I’m looking at some new tires. Or is it something I shouldn’t be worrying about right now. Being new and haven’t done my first track day yet
 

Bill Pemberton

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With 3.73s go with the 295s , since you are learning you want as wide a footprint as possible , imho. The main tracks you will run are more momentum tracks and some of the higher speed sections are in turns , so go with more meat on the ground ( width).

As new to the sport , the 285s probably still would be okay with the 3.73s , since none of the tracks listed has a long straight like VIR, Pocono, Road America, Road Atlanta ,etc. There are some very quick sweepers and turns that are 80-95 mph, so grip is more important. Not sure that the top speed at Hallett , Topeka , Hastings or Cresson ( short course ) would be much over 110 ( with the V6 ), but each of the tracks have some high speed turns.

Good luck, and a 295/40/18 Falken 615K+ is $240 right now , whereas the Hankook RS-4 is special order and $284 each, if that makes any difference? Lots of choices and Duane Black is an excellent guy to chat with, see what he thinks , as he also is running a 6 cal. Stang. Hit the link for Tire Rack as that is what I based the pricing on.
 
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With 3.73s go with the 295s
So just to clarify you mean, 295’s in 35 or 40’s? Just making sure. I am hoping to get some 295 but there is a steal of a deal with a guy selling some 285/35 Super Sports with a couple hundred miles that I’m considering because of the price And I feel like I won’t be reaching the limits of it on my first couple track days. Am I wrong on thinking that?🤷🏽‍♂️ If not those, then I’m really looking to the RS-4
 

Bill Pemberton

0ld Ford Automotive Racing Terror
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Blair, Nebraska
I would probably get the Falken Tires or the Hankook RS-4s ( there was a deal on those Falkens ) , but to make sure you are talking about the Michelin Super Sports and not the Michelin Pilot Sport 4s tires?
 
The ones I’m specifically talking about are the Michelin Super Sport. Someone near me has a barely used set. If I could get the 4s new I would. But right now, I think that is going to be getting above what I can buy.
 

Bill Pemberton

0ld Ford Automotive Racing Terror
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Exp. Type
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Blair, Nebraska
Your choice , those are essentially over a decade old design , but still a decent tire. They won't have the grip of the other two , but if super cheap seat time is always worth alot and sounds like that is your main focus now -- commendable. Work on technique, study the track and get Instruction , speed always comes, especially if you learn solid habits, while shedding any of the bad ones you might have.
 
You’re right, I’m really just wanting to have good enough tires for me to get some seat time. The ones I have are NOT up to much spirited driving. Thank you for the help, hoping to be going to Hallet for some track days within the next couple months when I’ve got some time off!

Edit:After some closer inspection, the tires are 4s. Hadn’t noticed and thought they were super sports. My bad
 

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