I have the Sport rims with Kuhmo Escta 4X tires on my 2005 G35 sedan 6MT that I have had for only a couple of weeks. The tires are going to need replacing in a couple of months and I live in michigan so I am only considering ultra high performance all season tires, no summer or slicks, etc as we get unpredictable weather here.

Since I will be needing to replace the tires, I want to lose weight at the same time if I can do it, as I have done about 80lbs of weight reduction throughout the car and I can def feel the difference over the car stock when I got it. My minimum goal is to remove 40+lbs of rotating weight on the wheels and tires to improve acceleration, braking, handling, and fuel economy.

I have researched that my stock 18x7.5 sport rims that they weigh about 24.5lbs each without tire. I am trying to find a 18x7.5mm 17-18lb rim that costs less than the enkei RFP1's (I dont want these rims because I live in the worst state with potholes, I have bent atleast 7 rims over the past 25 years of driving. I have found the 18.1lb tracklite 5 spokes at tirerack on sale for like $179 right now but they are 18x8 and I kinda want to keep everything in the stock configuration of 18x7.5 235/45/ZR18, unless someone here can direct me otherwise. Oh BTW, this is only for driving around on the streets leisurely and enthusiastically. I am not a drag racer, burnout artist, track driver or drifter. However I must have the feeling of having "proper running shoes" on, rather than a pair of heavy work boots. I have owned many cars with heavy rims and I cannot drive around with that heavy bloated feeling. I like light as a feather, nimble and rapid.

The tires I am currently using are the Kuhmo Escta 4x tires, which weigh a hefty 27lbs each according to online data. these are getting towards end of life. The tires I am considering are the General G-MAX AS-03 tires, 235/45/ZR18. These tires weigh 22lbs, and are the lightest 235/45/ZR18 I have found so far, that is for a ultra high performance all season tire. If anyone knows of a lighter UHP A/S tire that performs just as good, please let me know.

Right now my car my stock sport rims and kuhmo escta 4X tires weigh 51.5lbs per wheel. Since I need tires sooner than later, If I JUST replaced the tires with the general G-maxes, that will shed about 5lbs per corner, or 20 pounds of rotational weight, that should be noticeable until I get new rims. This would bring my stock rims with G-max tires down to approx 46.5lbs per corner. Now if I replaced the stock rims out with a (?) set of 18x7.5 rims that weigh approx 18lbs per rim, I would be saving 6.5lbs per corner with the rims upgrade, or another 26lbs overall and make my final wheel/tire weight at approx 40lbs even. This would mean the total weight loss per corner would be 11.5lbs, or 46lbs overall (with new 18lb rims and 22lb tires). There is no doubt that 46lbs of rotational weight loss will make a huge impact on everything and make me want to go out drive around for pleasure more often,as the car will be putting more power to the ground. I will also be removing more weight by upgrading the rotors to lighter weight 2 piece versions in due time so this will also help as well.

I would be interested to hear of anyone who has done this.

 

I have 18lb wheels and it does make a little bit of a difference but not much. What makes a HUGE difference is shrinking the diameter of your tires. When I first got the wheels I put 265/35 tires on them (2.75" sidewall) and that **** took off like a rocket from 75-90. It looked dumb tho, so I put 275/40 on (3.5" sidewall) and now it looks good, but the performance is lacking. Are you lowered at all? If you're low, I'd take off as much diameter as possible, it's a MUCH higher performance upgrade than weight reduction. Or do both.

 

I am 100% stock 2005 G35 sedan 6mt, the only mods are k&n drop in, remove power port duct and approx 80lbs of overall practical weight reduction. Stock suspension and heights.

 

I know the price would be higher but they'd be so worth it
Lighter and much higher quality than the enkei
Much

https://www.ebay.com/itm/122028631951

Their downside is a +50 offset which is no no but just to show you there's a few other options out there that aren't crazy expensive

 

Lot of +43 offset options on eBay also (I really don't know what the sport 18s have for an offset for the sedans)

 

+50 is high, but it could work on a sedan with a 25mm spacer. When I traded my wheels the dude had a sedan and my 7 spokes sat almost flush with no spacers and those, I believe, are a +30.

 

I think your best bet are those 18.1 lb wheels from tirerack, and they are only a 1/2 inch wider than your stock wheels. It will still be a significant weight loss from your stock wheels.

 

Thanks for the responses and ideas guys. What I am going to do first is replace the current worn down tires (kuhmo escta 4X) with the General G-Max AS-03 tires on the stock sport sedan rims in the next month or so and I will report back. Back about 15-16 years ago, I had Team Dynamic Motorsports and Konig Traffiks on my 2000 Contour SVT and I bent 3 rims here in Detroit with our terrible potholes and cracked up roads and that was a mess to deal with so I am going to try the lighter tires out first since I need those sooner than later and hold off on rims at this point in time and see what dropping approx 5 lbs per tire does first. When I went from the TD motorsports to the lighter Traffik rims (same size, just different rims), the difference was substantial, you could feel more power going to the ground and the car (would spin the tires more/easier than before) had more of a feathery feel to it, better pull thru gears and the top end seemed better over 90mph than before. So the way I look at it everything helps in the end. I only go to the store or such but I like to open it up sometimes on our 55mph roads that have stoplights every mile, perfect for 0-60 test runs or dragging someone (seems everyone floors it off the lights around here).

 

Honestly rpf1's are built like tanks....everyone has them for a reason because they are tried and true...i would honestly look for a used set. Chicago is just as bad on roads, and a lot of folks daily rpf1's out here. Good luck

 

I will look around for some RFP-1's on the used market. I am getting the General G-Max AS-03 tires in a couple of weeks, they are on a special promotion right now through an online retailer where if you buy them online them you can get free installation in their stores so I am taking advantage of that, I went around town and was price quoted $116-150 more so I am taking advantage of this 1 month online promo. I will be losing roughly 5 pounds per tire so I will report back what I felt and how the car handles with the new tires.