Help me understand tread depth and drag radials....

[clg82]

Hello everyone, the previous owner before me installed some 285/40/18 Nitto NT555R drag radials. I have never had drag radials before and am unsure of how much life these actual tires have left on them. and what PSI on the street I should be running them at. Here is a picture of the tires and the tread any help would be appreciated.

[2002ssslp]

I had the same tires on my 02 SS and I ran them at 32 psi cold around town and dropped them to 18 to 22 psi when racing. They have wear indicators in the tread so you know when they are done. Yours are getting real close.

[clg82]

I appreciate the response. Looks like I'll be needing to get new reads soon than. They currently are 285/40/18 what would be the downfall of going with 275/40/18 for new tires?

[35th-ANV-SS]

I had the same tires on my 02 SS and I ran them at 32 psi cold around town and dropped them to 18 to 22 psi when racing. They have wear indicators in the tread so you know when they are done. Yours are getting real close.

Same here.

[2002ssslp]

I appreciate the response. Looks like I'll be needing to get new reads soon than. They currently are 285/40/18 what would be the downfall of going with 275/40/18 for new tires?

No downfall at all. Go for it.

[35th-ANV-SS]

Less sidewall....not much difference between the two though really.

[clg82]

thanks fellas for the responses...I may go with the Nitto Nt555 (non radial) for the rears since I have read nothing but great things about them in the forums here for good street and track driveability.....I don't really need a tire that's great in wet or rainy weather unless so-cal decides to come out of this drought that we're in....:rofl: anyone suggest a different tire besides the nt555 or does that seem to be the way to go?

[Whamhammer]

thanks fellas for the responses...I may go with the Nitto Nt555 (non radial) for the rears since I have read nothing but great things about them in the forums here for good street and track driveability.....I don't really need a tire that's great in wet or rainy weather unless so-cal decides to come out of this drought that we're in....:rofl: anyone suggest a different tire besides the nt555 or does that seem to be the way to go?

Do they have a 285/35/18? That would be closer to stock tire height.

[clg82]

Do they have a 285/35/18? That would be closer to stock tire height.

I am really unsure on what the numbers actually mean...I could check to see if they carry the Nittos in that tire size but what would going from a 40-35 do if anything as far as performance? or look?

[35th-ANV-SS]

The first number, in this case 285, is the width of the tire - it is measured in mm. So, 285mm. The second number, 40, is a percentage of the first number, and represents the side wall height. Therefore, 40% of 285mm, or 114mm. The last number, 18, is the rim size.

285mm = 11.22"
114 mm = 4.49"

[35th-ANV-SS]

As comparison, a 285/35R18 tire would be:

Same tire width, 285mm
Side wall height = 35% of 285mm = 99.75mm or 3.93".

Therefore, this tire would be overall shorter than the previous 285/40R18 tire since the side wall is not as tall.

4.49" - 3.93" = 0.56" x 2 (top and bottom side wall) = 1.12" shorter.

Make sense?

[kingls1]

I was doing some tire shopping today myself. Looking at the Nitto NT05R drag radial. Read some good stuff on them. Not my daily driver and only in the rain 5 times in 4 years so not really a concern however 2 of the 5 was headed north to the track. I would like a set of track wheels and tires but budget for that not good and only a few track days a year so right now tires on my rims makes sense. Check them out they look great and I found some great deals on ebay with free shipping

[35th-ANV-SS]

The NT05R is supposed to be a more friendly track-oriented tire than the NT555R. If you ordered them, let us know how you like them. I got my Mickey Thompson Street Comps delivered today which I'll be using up front.

[clg82]

I have decided to go with the Nitto NT555 275/40/18 tires for the rear and will be ordering them this evening.....hope i made a good choice.

[kingls1]

I'm pretty sure I'm going to order them 275/40-17 $392 for 2/ free shipping. After some thought over the past few days I think I'm going to in the spring pick up 2 more rims to match what I have and put my street tires on one set and NT05's on the other. I love the look of my wheels and this way I can use the Nitto's on play days and still retain the look.

[35th-ANV-SS]

The Mickey Thompson ET Streets will hook a lot better

[clg82]

The Mickey Thompson ET Streets will hook a lot better

from what i've seen they don't make them in 18s.

[35th-ANV-SS]

You are correct. That message was for Jeff. Sorry.

[clg82]

You are correct. That message was for Jeff. Sorry.

No worries buddy.

[kingls1]

The Mickey Thompson ET Streets will hook a lot better

I beg to differ my good man...Nitto NT05 Drag Radial Vs. ET Street Radial II Tires - Super Chevy Magazine Read on