16 in or 17 in rims? Help!
- Thread starter rdemattio
- Start date
For ride and cost, go w/16's.
For looks and performance go 17 or even 18.
And BTW: If going to 17's, AND going wider, the closest match is a 225/45. They are juuusssttt a tad shorter than an equivalent 205/50, but certainly not enough to make any kind of a difference.... like .15mph @ 60.
Those 215/40's hatter is talking about are way short. Even a 215/45 is shorter than the 205/50's.
I've considered dropping to a 16" multiple times just to save money when replacing tires. The main problem is currently my tires go out in axle pairs about 8k miles apart from each other. I'm not too concerned about a drop in performance and handling since most of that is due to the suspension. I mean even a Mz3 with stock 16" wheels still handles great. If I ever come across an inexpensive set of 16x8 rx7 FD wheels then I'll probably spring for them. Plus they're lighter than stock so less unsprung weight. Here's a pic on a Mz6 (though I'd stay with silver)
IMHO the benefit in decreased cost, smoother/quieter ride, and decreased chance of curb rash (wheel is higher off the ground so less likely to hit curbs) makes it an easy choice.
IMHO the benefit in decreased cost, smoother/quieter ride, and decreased chance of curb rash (wheel is higher off the ground so less likely to hit curbs) makes it an easy choice.
Yes 215/40 is too short but they were mounted on the wheels when I bought them, so why not burn through them. I was not suggesting using that size to him, just letting him know what I am rolling on.
Your post wasn't clear about that so I wanted to make sure other readers understood.
You must be racking up the miles w/those too. I haven't checked but there must be about a 5mph difference running those 40's. That'll add miles to the odo that aren't really there.
My first set of replacements were 215/50's on the OE wheels and I could feel the car was just a little bit more sluggish off the line.
When you go back to correct size tires, you are likely to experience that too... only because you are effectively iincreasing the final drive ratio using the 40's. Like the difference between a 4.30 then going back to a 4.10.
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Very true, especially these days. tires aren't just the black, round donuts that hold up the car anymore.
If the OP will allow me one more off-topic comment: I wasn't too far off in my estimate. I did the calculations and running 215/40's you are going approximately 61.63mph when the speedo indicates 65. There is a difference of -1.3" in overall diameter, -4.08" in overall circumference and an additional +43.97 revs/mile traveled. They should burn up pretty quick. But I'll bet the car feels pretty quick off the line too?
Yes it does feel quicker on take off, partially the tires and partially the 17.5 lb. wheels. I also notice at highway speeds the revs are up and I need to run a bit faster than I normally would.
As for the purpose of this thread, I would recomend staying with the stock size tire/wheel package 17x6.5 or 7.0 with 205/50/17. The speedo will read correct and it is a pretty popular size of tire and should not cost too much. Not to mention the fact that you won't have to run giant sidewalls in order to run 16" wheels and keep the same aspect ratio as running 17".
As for the purpose of this thread, I would recomend staying with the stock size tire/wheel package 17x6.5 or 7.0 with 205/50/17. The speedo will read correct and it is a pretty popular size of tire and should not cost too much. Not to mention the fact that you won't have to run giant sidewalls in order to run 16" wheels and keep the same aspect ratio as running 17".
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That's a tall order because there is lots to understand, but I'll try and also to make it as simple as I can. You can get the more difficult technical stuff later.
OK, Tires: A 215/50-17" means 215= 215mm (8.465") tread width. The 50 is a percentage and relates to the sidewall height. So 50% of 215mm= 107.5mm (4.23") of sidewall height. 17" of course is the wheel diameter. So to get a rough idea of the overall diameter of the tire, you would add 17" to 4.23 x 2, which in this case = 25.46". But that would only get you there roughly. Every tire and manufacturer are slightly different. Those are the "basics" of reading a tire.
One other thing: When the sidewall of a tire says 50psi MAX, that does NOT mean you should run the tire @ 50psi, but that exceeding that spec could cause the tire to blow out or separate under load conditions... and we wouldn't want that. Check your owners manual and door sticker for proper inflation for any given vehicle.
Wheels: Here's where it may get confusing to the novice, so hang on.
Everyone knows that a 17" wheel means that the diameter (and tire you should chose to put on it) is 17". And most people know that a 17 x 7 wheel means that it's a 17" diameter, 7" width. But here's where it can get tricky.
There are two schools of thought about spacing, offset and back spacing. Spacing is either the distance from the center of the wheel (7"/2= 3.5", or in the case of the OE's, 6.5"/2=3.25" Center) to the mounting flange (offset,) In our case, the offset of 52.5mm forward (outside) of center.
The other method is called backspacing, or measuring the distance from the back of the wheel to the mounting flange. But this changes with wheel width and is less accurate for that reason.
Our cars, as with most FWD cars, have a positive (+) offset. This means there is more wheel behind the mounting flange than in front of it.
What are often called deep dish or deep offset wheels, such as you see on drag cars or muscle cars or RWD/4WD cars in general are negative (-) offset wheels. This of course means the opposite of a positive offset, or that there is more wheel sticking out past the mounting flange
Backspacing is only useful if clearance between the wheel and suspension is already limited and you are going wider... usually MUCH wider. Example: With the OE 6.5" wheels, +52.5mm offset you might only have another 1" before rubbing the suspension occurs. But you want to install 10" wide wheels, though that's a lot of wheel!! Because you know they will rub, you have to consider the factory offset is null and void, but useful as a reference for determining the new offset. 10" - 6.5"= 3.5"/2 = 1.75" -1" (original clearance to the suspension) = 0.75". That's the clearance you would need, so you would subtract the difference of 0.75", or 33.86mm from the 52.5mm you already have to determine what offset you would need to work. Your new offset would be 52.5mm - 34mm = 18.5mm, and that would give you the clearance you need, but that much difference would cause all sorts of other problems too.
This is JUST an example. Please do not try putting 10" wide wheels on your car.
WHEW!!! that's enough for now. Let me know if this makes any sense to you and if you have any other questions.
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And I was trying to be as gentle as possible too......
But he's right. It's a lot to take in if you don't already have the mindset for it.
Almost time for new skins here, I've been running 225/40's on 18x8 rims. I know I'm SOL on the width and tire meeting road, but that's about as close as I can get speedo-wise to stock correct? Sorry for minor threadjack
225/40's are as perfect as a plus 1 gets. What's the problem? This difference is so close it's not even worth mentioning.
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I used an extreme example to help drive the point home... so the differences would be higher and hopefully make more sense to you.
Well, I'm glad you were able to understand most of it. If you keep after it, and find some helpful tools, much will become second nature to you after a while.
Congrats on your first lesson of wheels!!
active-trend
Member
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- MAZDA MX5 2012 GT
Smaller wheels(small rim with bigger tires): less effort to turn, quick take off, but more turns required while running at higher speeds is like having a dime keep up with a nickle on revs.
Bigger wheels (Big rim with low tires): Feel the road, better high end, a bit slower on take off untill it grips, did I mention feel the road...literately..
Bigger wheels (Big rim with low tires): Feel the road, better high end, a bit slower on take off untill it grips, did I mention feel the road...literately..
