Benefit of going to 215?

[IrishST]

I'm sorry for making a new thread, but tires/wheels are not my area and I've been reading until I'm blue in the face and still a little lost on what I should do. Here's my initial mod plans:

Cobb Stage 1 package (drop in, AP, RMM kit)
Cobb sway bars
Cobb lowering springs

In the future I will likely take it further, but that's a few years out so I'm not concerned about that right now. My use is daily driving, spirited backroads, and while I can't rule out track time or autox, it isn't a big thing for me right now. This brings me to the wheels and tires and my source of confusion on what I should do.

I was considering bumping up to a 7.5" rim, staying on 17", and from what I've read it looks like a 215/40/17 is the right fit. I do not want to have to deal with rubbing and modifying the wheel wells, or rolling the fenders, so fit with the Cobb springs is important. From what I gather, a 42+ offset is what I should be sticking with and this size combination should work?

I was hoping some of the more experienced tire/wheel peeps could help me with the following:

1. Is an increase to 7.5" and 215 width worth it the money it will cost? I do want black wheels but I can easily get the stockers painted or powder coated (I actually think they look nice and don't 'need' to swap them just for looks) and probably save a bunch of coin if there is no real performance gain to be had with the slightly larger size.

2. Assuming a worthwhile performance increase, am I at a good place when it comes to size? Should I go larger on the sidewall to 45? Stay at 40 but pump the width up to 225? I heard 225 rubs when lowered and requires rolling the fenders and stuff which I'm trying to avoid.

I really appreciate any insight you experts can pass my way so I don't make costly and worthless mistakes in this area.

Thanks!!

 

[commonplatypus]

215 is going to likely increase the diameter no matter what. The number you should be looking at is going to be tread width and section width more than the vague number in the "size" of the tire. a 215 will fit fine on either a 7" or 7.5" wheel (It will protrude a bit over depending on sectional width more than a 205 tire. The other thing to consider is that some 215s may not have a larger tread width than even some 205 width tires.

This question mostly depends on what you want to do with the car, though. It sounds like you want a daily driver and for that I would stay 205 and pick a high quality tire that has both decent dry performance, as well as decent wet performance. You're lowering your car, so that makes it questionable on whether or not you can handle a 45 over a 40 tire.

 

[Fasta123]

215 is going to likely increase the diameter no matter what. The number you should be looking at is going to be tread width and section width more than the vague number in the "size" of the tire. a 215 will fit fine on either a 7" or 7.5" wheel (It will protrude a bit over depending on sectional width more than a 205 tire. The other thing to consider is that some 215s may not have a larger tread width than even some 205 width tires.

This question mostly depends on what you want to do with the car, though. It sounds like you want a daily driver and for that I would stay 205 and pick a high quality tire that has both decent dry performance, as well as decent wet performance. You're lowering your car, so that makes it questionable on whether or not you can handle a 45 over a 40 tire.

I don't know much about tires either... My cars not lowered nor do I plan on it, I also plan on keeping the stock rims. I'm stage 3 so I'd like som wider tires that leave more of a footprint, I want to improve my acceleration. What size and what tire would you recommend for 100$ or less? Can I fit 225 without rub around corners or bumps?

 

[Wimp Lo]

For racing, you want the lightest and widest tire you can fit but in a sanctioning body like the SCCA or NASA, changing the wheels in certain ways might bump you up in to a tougher class. I think in SCCA, you can change diameter up or down 1" and stay in the same class but width changes bump you up. Wheel offset is usually +/- 6mm without going up a class.

On the street, if your streets are as bad as they are around here, a 205-40 just doesn't have very much sidewall to absorb the hit it takes going in to a pothole. I like a taller sidewall for the street.

I went with a 16*7" wheel, 42mm offset (stock is 47.5mm I believe) so they should not bump me up a class. For the tire, I chose a 215-45r16. That tire closely matches the OE tire diameter so the speedometer should be accurate, the tire fills the wheel well pretty well, the tread is a bit wider for more grip, the sidewall is taller to take potholes better, the wheel is lighter, the tire is about the same, etc.

The tire I chose has a stiff sidewall which negates the normal handling tradeoff of a taller sidewall.

The negative of the setup it that 215-45r16 tire choices are slim and because of that, there are not many good 16" wheel choices.

I wound up with a BFG Rival and the tire noise is rather annoying for a daily driver like mine but as race tires they would be fine.

If it wasn't for the tire noise, I would say it's about as good as you can get for a dual purpose wheel/tire combo.

 

[IrishST]

I appreciate the info folks. I'm honestly not sure what I'm going to do at this point when it comes to my wheels/tires and my initial mod plans. I would really, really, really like to get a set of Pilot Super Sports, but it looks like I'd need to go 215/45/17 as they don't do 215/40/17 or 205/40/17 in that tire. This means a taller sidewall, about 3% speedo inaccuracy, and if I do end up lowering the car with springs, or eventual coilovers, it could lead to the problems I don't want such as rubbing.

I would really like to stick with 17" over 16" because I just prefer the way it looks. I would very much like to get a little wider on the tire for more contact, but as I said in the OP, I'm not really into serious autox or tracking so it's all in the name of frequent back road fun more than anything else. I may just stick with the stockers, powdercoat them, and go up to the 215/45/17 PSS's and not do the springs. I dunno...

 

[RAAMaudio]

I have to keep posting this so often maybe I should write something up which includes a chart of actual specs to submit as a sticky.

You cannot simply go by a posted tire size as those are arbitrary numbers, the diameter is the only constant.

To properly fit the best width tire you must look at the measured section width and tread width being the primary ones to use as they can be considerably different than the sidewall numbers would suggest.

A good general rule of thumb is to have the tread width slightly narrower than the wheel width for the best feedback and control if you are setting the car up for the best handling at higher speeds especially.

Sometimes it is best to have the widest tire you can fit on whatever wheel width you have for autocross use, emphasis on Sometimes.

Front of the car for drag racers as well, wider tires can mean faster runs but that type of setup can be quite detrimental to handling and in extreme cases a bit unsafe in some situations.

It is also very beneficial to look at tire weight as it effects every single aspect of performance as well as ride comfort and wear and tear on the chassis.

 

[milkman42]

I have to keep posting this so often maybe I should write something up which includes a chart of actual specs to submit as a sticky.

A great sticky could be made by simply copy-pasting/consolidating all of your excellent posts scattered across this forum!

 

[Fasta123]

I have to keep posting this so often maybe I should write something up which includes a chart of actual specs to submit as a sticky.

You cannot simply go by a posted tire size as those are arbitrary numbers, the diameter is the only constant.

To properly fit the best width tire you must look at the measured section width and tread width being the primary ones to use as they can be considerably different than the sidewall numbers would suggest.

A good general rule of thumb is to have the tread width slightly narrower than the wheel width for the best feedback and control if you are setting the car up for the best handling at higher speeds especially.

Sometimes it is best to have the widest tire you can fit on whatever wheel width you have for autocross use, emphasis on Sometimes.

Front of the car for drag racers as well, wider tires can mean faster runs but that type of setup can be quite detrimental to handling and in extreme cases a bit unsafe in some situations.

It is also very beneficial to look at tire weight as it effects every single aspect of performance as well as ride comfort and wear and tear on the chassis.

Please if you find thing the time do a short write up, I think it could benefit a lot of people. I rly don't have a clue what's best for me. Maybe if you could use some good tire examples that have been used on the fist by members with stock ride height and lowered and what are some good tires for handling, drag, all round. I know I'd srsly appreciate it.

 

[Rhinopolis]

Try this

https://www.tacomaworld.com/tirecalc?tires=205-40r17-215-40r17

 

[RAAMaudio]

Sorry, tire calculators are not the way to do this unfortunately as it would make things much easier

Perhaps in the truck world or general cars it is not a big deal but we have a pretty narrow window to work with on this car and many others being setup properly.

Tires are made using an aspect ratio, not actual sidewall specs which means diameter, section and tread width are not a given and not very close at times and some are so far off it is very misleading as to how they are labeled.

I have been busy with other things so no time to write it all out again but take a look at Tirerack.com at various tires and look at the measured specs huge differences in some tires, hardly anything is ever the same no matter how labeled except rim diameter.

You can also find quite a few posts searching mine and see exact specs posted on many tires(as exact as Tirerack measures them and they are generally quite good at it) Some tires they do not sell take a bit more effort to find the info and some just not out there.

 

[Rhinopolis]

Makes sense

 

[GAbOS]

Try this

https://www.tacomaworld.com/tirecalc?tires=205-40r17-215-40r17

Thanks for posting this. I have an old school one from a Miata forum. It's also good to note that there are plenty of Tire and Gear calculators for your mobile devices. I have both.

NOTE: As RAMM has mentioned. Tires are not made the same so a 205 is not really a 205. Every manufacturer will (has to) post the actual numbers for each tire. Do an evening of researching tread/section widths for all sorts of tires and you may be shocked at how wide a 205 r16 could be! Your next very important number to read from the actual released manufacture is the total height of the tire.

 

[IrishST]

So I've been trying to do more on my side regarding this question and I've found that the stock size, and 215/40/17 don't have a ton of selection. That said, there are some decent tires in that selection and I think I'm going to go with something like the Star Spec ZII if I decide to swap.

According to TireRack:

SS = 7.5" rim width, 8.6" section width, 8" tread width, 23.8" diameter
Stock = 7.5" rim width, 8.4" section width, 7.6" tread width, 23.4" diameter

Looks like I'll gain about .4" of tread while not increasing the overall diameter or overall width too much and should be fine on rubbing, even if I lower with the Cobb springs since those springs aren't too aggressive. That said, considering my uses, these tires might actually be a bit much so the search may continue, but that's my initial thoughts and I'll be sure to look at the physical size of any tires I consider.

Now I just need to figure out this offset thing for whatever wheels I might choose and I should be set. Thank you for getting me on the right track in looking at physical sizes and not just the specs stamped on the side, I appreciate it.

 

[Chuckable]

So I've been trying to do more on my side regarding this question and I've found that the stock size, and 215/40/17 don't have a ton of selection. That said, there are some decent tires in that selection and I think I'm going to go with something like the Star Spec ZII if I decide to swap.

According to TireRack:

SS = 7.5" rim width, 8.6" section width, 8" tread width, 23.8" diameter
Stock = 7.5" rim width, 8.4" section width, 7.6" tread width, 23.4" diameter

Following this thread for the good info. Maybe I'm misunderstanding, but I believe that the stock wheel width is 7 inches.

 

[IrishST]

Following this thread for the good info. Maybe I'm misunderstanding, but I believe that the stock wheel width is 7 inches.

The stock 'wheel' is 7" wide, however according to TireRack, the stock 'tire' is a wide 205 and has tread wide enough that its recommended rim size is 7.5". Here's the link to their page for our stock tire/size where I pulled the info, just click on the 'specs' tab:

http://www.tirerack.com/tires/tires...R7RE050A&vehicleSearch=false&fromCompare1=yes

 

[commonplatypus]

Just a quick note that those Cobb springs (If you do decide to go with lowering the car) you are looking at are just re-branded Eibach springs. Literally nothing different about them. They are the exact same item. The Eibach's can be had anywhere between $50-$70 cheaper than the Cobb set from many different vendors.

 

[IrishST]

Just a quick note that those Cobb springs (If you do decide to go with lowering the car) you are looking at are just re-branded Eibach springs. Literally nothing different about them. They are the exact same item. The Eibach's can be had anywhere between $50-$70 cheaper than the Cobb set from many different vendors.

Appreciate the heads up, that's good to know. Are we certain there is no difference in tuning between the two, though? I knew they were rebranded originally but I was under the impression the Cobb's had a different spring rate.

Also, for the experts, new question regarding tires - I'm going to dual set and get an ultra performance all season for colder months since we see very, very little snow here and the temperatures get too cold for summer rubber, but not so cold that all season is a big problem (lows in the upper 20s at night when I'm not doing much driving w/ average daytime lows in Jan/Feb around 35 on cold days). This being the case, I'm not afraid of a super high performance summer set that only gets 15-20k since I'll only use them from like late April, early May though September or so and I fortunately have 0 commute for work since I work from home. I was looking more at the Star Specs in 215/40/17 and was wondering if a 7" rim width would be sufficient. I understand they are better suited to a 7.5", but the low end of the acceptable range is 7" so if anyone has an opinion I'd like to hear it.

I'm just weighing options on wheels and if those tires (Star Specs - 215/40/17) or something similar will work on 7" wide rims without compromise I can keep the stock rims for a bit and actually have only the tires swapped out for the seasons. My likely end goal is using the stock rims for my all season tires and aftermarket for the summer tires so I can swap myself in the driveway, but I don't hate the stock rims as I mentioned earlier and I'd rather sink rim money into other things first and come back to them later.

 

[RAAMaudio]

Since going with a summer setup why not really do it right and go for wider and lower weight at the same time gain a better ride which is less wear on the car. The lower weight and wider setup will provide improved grip laterally not just because of width but also because they will maintain contact better as the suspension will work more effectively. You gain in acceleration and stopping performance as well, lower weight wheels and tires when done right improve every aspect of performance.

Check to see what it would cost to run 15x8 TD wheels and 225/45/50 Rival S, Kumho V720, Proxis R1R....I run the Rival S in that size, V720 was not out yet or I might of picked it R1R is a bit old school now.

As an example of ride quality improvement I just gave my daughter a barely used set of Michelin PS-3 A/S tires, 205/45/17, 7.5" wide tread, they road like a brick even on 16.8 lb wheels, high noise, harshness, we could barely stand them on the car. I put the Rival S back on and the ride in hugely improved, noise and harness gone.....so much better I am considering going to a stiffer spring and I already have the race set of springs on the coilovers.

I just looked into the V720 a bit more, it seems Tirerack is the only source, not all specs are posted and shows only 2 tires available so a call to them is in order to see what is going on.

The Rival S is doing well for me, on a warm day, big turbo, LSD, no wheel spin in 2nd gear even when it spools up late and hard like my car does, it just rockets off I can pound the brakes and come to a stop in a very short distance, no ABS kicking in, cornering grip is very very good, feedback is great(enhanced in my situation by running 9" wide wheels)

There are some good 16" tires but not much choice in wheels, I have 16x8 Enkei RPF1, 4x100, for my new all season wheels, still deciding on tires, only went 16" as no 15x7 or 8 will fit over my custom BBK setup, I would prefer 15 and could save money and more weight!

 

[RAAMaudio]

There are more tire choices in 205/50/15 that might cost less, weigh less, still plenty wide for an 8" rim like the Star Spec, 19lbs, 8.4 section, 7.5 tread, $117 each.

Advan AD08R, 7.7" tread width, $135 so more money, very good tires but 180 wear rating, if you autocross they might bump you into a faster class than what is best for your setup.

 

[Fasta123]

Since going with a summer setup why not really do it right and go for wider and lower weight at the same time gain a better ride which is less wear on the car. The lower weight and wider setup will provide improved grip laterally not just because of width but also because they will maintain contact better as the suspension will work more effectively. You gain in acceleration and stopping performance as well, lower weight wheels and tires when done right improve every aspect of performance.

Check to see what it would cost to run 15x8 TD wheels and 225/45/50 Rival S, Kumho V720, Proxis R1R....I run the Rival S in that size, V720 was not out yet or I might of picked it R1R is a bit old school now.

As an example of ride quality improvement I just gave my daughter a barely used set of Michelin PS-3 A/S tires, 205/45/17, 7.5" wide tread, they road like a brick even on 16.8 lb wheels, high noise, harshness, we could barely stand them on the car. I put the Rival S back on and the ride in hugely improved, noise and harness gone.....so much better I am considering going to a stiffer spring and I already have the race set of springs on the coilovers.

I just looked into the V720 a bit more, it seems Tirerack is the only source, not all specs are posted and shows only 2 tires available so a call to them is in order to see what is going on.

The Rival S is doing well for me, on a warm day, big turbo, LSD, no wheel spin in 2nd gear even when it spools up late and hard like my car does, it just rockets off I can pound the brakes and come to a stop in a very short distance, no ABS kicking in, cornering grip is very very good, feedback is great(enhanced in my situation by running 9" wide wheels)

There are some good 16" tires but not much choice in wheels, I have 16x8 Enkei RPF1, 4x100, for my new all season wheels, still deciding on tires, only went 16" as no 15x7 or 8 will fit over my custom BBK setup, I would prefer 15 and could save money and more weight!

Thanks for posting, those 225/45/50 tires you listed can I use those on the stock rim with no rub ? I'm looking for a good sticky tire to help with acceleration but also has good tread wear and a reasonable price. I live in California so it never snows and rarely rains. Thanks for your help. I never really track just some spirited bac road driving.