Gatson1983

iTrader: (1)

Hi guys,


First, I apologize if this topic has been beaten to death and there is a dedicated thread; I did a search and I honestly couldn't specifically locate this information.


I recently purchased a set of wheels from CariD.com. I bought 19x8.5 Spec 1 SPM 75 wheels and put 245/40/19 Toyo Proxes 4 Plus around them. Goodness, a very aggressive stance compared to the stocks I was running. And the tires are quite satisfactory as well!

Here's my problem; acceleration lag. Don't get me wrong, my car is still more than capable, but it feels very sluggish when compared to how it was before the new wheels and tires. After doing some reading about this, it seems to be an issue of tire width, or the weight of the wheel+tire, or a combo of those.

I'm coming from stock 17inch OEM wheels and tires for a 2011x Sedan. I found that my wheels are essentially 27lbs each, which, to my understanding, are substantially heavier than what I had.


My question then stands at is the weight of my new wheel the likely culprit for the performance loss? Or is it the width of the tire?


Many thanks in advance.

PNW_IPL

iTrader: (5)

Very likely. Same thing happened to me with my 350z nismo. I swapped out the oem forged rays wheels for a set of varrstoen es6 19x9.5 265 35 and 19x11 295 35 and my car was noticeably slower. Nothing an exhaust hfc and a tune couldn't fix though. Recently ditched the wheels in favor of the oem forged setup and wow my Z pulls very nicely now.

JSolo

iTrader: (14)

Heavier wheels + stickier tires = more resistance.

I'm not sure which tire you came from, but the above is considered a high perf all season, so likely somewhat sticker than stock.

I notice a change immediately when switching to/front the winter tires. They are 225 all around and considered low rolling resistance. Car feels lights. With the summer tires back on, it has a somewhat heavy feeling (esp now that they're older and more worn).

chuckie311

iTrader: (3)

Good article about wheel size and how it effects gas mileage and performance

Effects of Upsized Wheels and Tires Tested - Tech Dept. - Car and Driver

Black Betty

iTrader: (60)

Simple answer - Absolutely. Your larger diameter much heavier wheels are definitely why you've lost aacceleration. Think about it from a simple physics standpoint. The tires are not the problem. They have more grip which aids acceleration, but the larger diameter and heavier weight of the tires in 19" vs 17" size probably offset any benefit from the extra grip.

Find the weight of the original wheel/tire combo on each corner and compare it to the weight of the new wheel/tire. This increase is why your car is slower.

VenomGT9

iTrader: (4)

Rotational mass is a killer

Gatson1983

iTrader: (1)

I see. Thanks so much guys for the speedy response and support! The wheels that are on there are coming off ASAP. Sure, they look good, but I didn't purchase this car to just cruise, I want performance. Completely understand about diameter and having to rotate more mass, but was getting conflicting answers with regard to the added weight.

I'll be looking at a set of forged wheels around 22lbs then. Anything lighter than that is out my budget.

Black Betty

iTrader: (60)

If you switch to a 22# wheel from one that weighs 27 now, I can guarantee you'll be very happy with the resulting acceleration increase.

chuckie311

iTrader: (3)

Forged wheels are going to cost way more!!
if you dont have a set rim in mind and want to reduce weight look at enkei

they may not be what you looking for but if you want weight savings these are awsome..starting at 18lbs for 18inch

https://www.getyourwheels.com/view-w...i-rpf1-silver-

Gatson1983

iTrader: (1)

I ended up purchasing a set of 19x9 Forgestar F14s in gloss Gunmetal Gray. 22lbs. Should have done that in the first place.

chuckie311

iTrader: (3)

dont trust what they tell you on the website weigh them when you get them.. from what i looked up a 19x9 weighs 24.7 pounds

19x8.5 weighs 23.8
19x10 weighs 25

look at post 20

Official Wheel Weight Thread. - Page 2 - Nissan 370Z Forum

JSolo

iTrader: (14)

Do we have any documented numbers on what the stock wheels weigh in the various trims (journey, awd, S, sedan, coupe)?

We got some numbers here already:

chuckie311

iTrader: (3)

I can weigh mine tonight and post the weight I had stock 17x7.5

chuckie311

iTrader: (3)

Just weighed my stock wheels 47.9 pounds 17x7.5

Black Betty

iTrader: (60)

Your wheels are forged form solid osmium?