215/40/18 or 215/45/18?

I have a 2000 3.0 EX Coupe with ABS. I was told that if I go with 40 profiles, then my ABS and speedometer would be off. Does anyone know how bad it will effect my ride? Please respond asap since I have 215/40/18 Yokohama Prada Spec-2 on order!

Thanks!

[ebpda9]

first i will need to know the stock tire size on the car

I'm not sure what the V6's have, but I think they've got some 205's on them. Not sure if it's still 15" or bumped up to 16" either.

According to Tirerack then your car comes with 205/60/16. If that is the case, then 215/45/18 would be a ver close match, within 0.07" of stock diameter, in other words it's negligible. 215/40/18 would be almost 1" smaller diameter, in other words very bad choice.

The I4's have 195/65/15 on them, thus the correct tire size for 18" wheels would be 225/40/18. That would yield the closest match to the stock tire diameter. If you went with 215 then 215/40/18 would still yield the closest match to stock. 215/45/18 would be over .6" larger than stock diameter which could affect ABS.

b

[ebpda9]

why it would affect the abs ? doesn't abs make sure that all the wheels have constant speed or doesn't let the wheels lock ? as long as the wheel is turning i don't see a problem

I believe they are 205/60/16's, I know the rims are 16's. When I was buying tires at Tirerack.com, the guy said 40's are a bad choice because of weight issue and ABS. He said all the Accord V6 with 40's or less have a high tendency to blow out because it will not sustain the weight and that 40's or less is for show and should not be used as daily driving tires...

The thing is, I see so many V6 Accords with 40's or less...so whats up?

[ebpda9]

40 is not an actual measure: it is the ratio of the sidewall to the tire width. they might have wider tires that's why they are 40's

Hmm, so lets say that I got 225/40/18, would that work? I am not talking just about fitting but the whole diameter shindig Spooge was talking about...

205/60/16 (stock) diameter: 25.686 in.
225/40/18 diameter: 25.087 in.
225/45/18 diameter: 25.972 in.
215/45/18 diameter: 25.618 in.
215/40/18 diameter: 24.772 in.

Best match is the 215/45/18. If you want wider tires, then you will either be .3" larger or .6" smaller diameter. I'd pick the .3" larger over the .6" smaller just to keep a small delta.

The problem with ABS and TCS is that they can use calculations based upon the tire diameter. From the tire diameter then the car knows how fast you're going, for one. Since the ABS system is basically one that just pulses the brakes, the rate at which it pulses the brakes is very important. If it is programmed to take a speed measurement, pulse at a rate, then evaluate effectiveness, then it could give you too little or too much braking before making an evaluation since its calculations could be thrown off.

Of course there are a variety of ways to program an ABS system and some could be more prone to problems than others when it comes down to diameter changes. Small diameter changes, like on the order of .25" shouldn't affect it at all since those can easily be varied by the load in the car, tire pressure, etc.

I wouldn't worry about it too much unless making a diameter change of, say, .5" or more. But that's just mere speculation.

I'm not sure how Honda's systems work, but as an example some ABS systems work well in snow and others simply lock up the tires. That just gives an idea of how much they can vary.

b

[Accord Man]

I would go with 215/40/18 .

with a 45 profile tire, on 18s, 225 would be the better choice. But 225, results in even more stress on the power steering.


So @ 215, with a 40 profile tire, you will be fine.

thats my pick.

this should solve the problem...

http://www.miata.net/garage/tirecalc.html