Tire help

[g_man1972]

Hi all, and happy new year to everyone.

I have a bit of a problem. When I bought my 92 super exceed two and a half years ago I neglected to check the details on the tires that it had. I have two miss matched sets, the ones on the back are fine and I'm trying to save money by only replacing the front two which really need to be replaced. The problem is that the rear tire size 225 80 15... this size doesn't exist here. And yes, I should have checked but they don't even have the DOT stamp on them, so I guess I am driving on illegal tires. I'm thinking of taking this up with the seller, but being as how it was so long ago, not sure of how much luck I will have. So my question is, would I be causing myself any problems if I get a size which is similar like 225 75 15 or 225 70 15? There seem to be a bunch of them around. Or should I say hell with it and get 4 new ones? How much of a deal is it not having the DOT on the tires?

Thanks to all for your help, haven't been around here much recently but glad to see the great group is still together and helping each other out!

Best wishes all
Gary

[Meanman]

You should get 4 new. If you chose to go with just two of dis-similar size when you engage 4x4 you can cause serious damage to the transfer case as the final ratio at the ground becomes different. Further different brands of tires of the same size can have a varience of sizes. Basically its no wider than , no taller than.
Hope that helps somewhat.

[Spearo]

There is really nothing more important on a vehicle than the tires. Besides the fact that 4x4 tires should be rotated more than a 2x4 and replaced 4 at a time, do yourself a favour and spend all the money on 4 (or 5) good tires and rotate them every 10 or 15,000km.
You have an awesome vehicle, don't hamstring it :)
Cheers,
Erik.

[Erebus]

Get 4 or 5 new ones, and spend as much as you can afford on them. Keep in mind that it is the rubber-road contact that decides if you are going to go where you want to go, or slide off the road, or skid into something. Don't skimp!

[g_man1972]

Well it seems pretty unanimous, that's what my gut was telling me anyway but the cheap bugger in me also had his say .

Although I would be interested to know still, ie the tires on the rear are Bridgestone duellers, 225/ 80 15, they are in good shape, 80-85 % tread left. That's why i don't really want to scrap them so early. I was thinking of trying to get some 225 75 15 of the same brand and model on the front. So my question is, will the difference in the second number make that much of a difference? Same height so no worries about 4 x 4, same rim size, just the other part i'm not sure about.

Thanks for all your input

[delicat]

Not so I'm afraid.

225/80r15
Width 8.85"
Diameter 29.17"
Circumference 91.64"

225/75r15
Width 8.85"
Diameter 28.28"
Circumference 88.84

So that's almost 1" difference on the diameter (or 3%). And if you look at what most people run those are the numbers:
235/75r15
Width 9.25"
Diameter 28.87"
Circumference 90.69"

If you need good tires I have a full set of 235's on original rims, it might help you.

Cheers.

[Meanman]

Second to David's comment, when dealing in metric sizing the first number ie 225 is the section width in Milimeters wile the second number is the percentage (80% in your case) of the width which makes up the sidewall height and of course the third number is the rim diameter. WHen dealing in Standard sizes (31x10.50r15) the first number is the overall tire height, the second number is the width and third once again is the rim diameter.

[g_man1972]

Ahhhh, thanks David. My appologies, I should have investigated more about tire sizes before posting that, I was decoding them wrong assuming the first number was the height like 30 x 9.5 x 15. so I was assuming that all 225 would have the same circumferance. Thanks for clearing up my error.

I'll send you a PM about your tires.

Cheers and thanks again.

Thank you too meanman, you posed just as I was posting the above.

[tigger]

It's important to have tires that are the same diameter for the reasons indicated above. Since diameter for similar tires (rim diameter, width and profile) made by different manufacturers can be different it's important to stick with the same manufacturer for all four tires. Further, it's important to stick with the same model of tire, as other models by the same manufacturer can have different diameters.

I'm not an expert with highway tires, but I know a little bit about off road (construction equipment) tires. In construction applications a diameter difference of more than an inch would cause a mechanic to change both tires when one is scrapped out. Since highway tires operate at much higher speeds, it's reasonable to assume the allowable difference in diameter would not be as great as with construction tires.

So the ideal replacement scenario is to have all new tires of the same make and model. If this isn't possible then you might want to look at other profiles to get a tire close to the diameter of the ones you want to keep. For example, the nominal diameter for your 225/80R15's is 29.17 inches. You might be able to find a tire close to that diameter, but in a different profile. For example, a 235/75R15 nominal dia is 28.87 inches, and a 245/75R15 is 29.46 inches. Both are within 1% of your current tire diameter.

Personally, I would go for 4 new tires, for the reasons mentioned. Tires are far more important than most people realize. If the life in your remaining two good tires is that important you can use them as short term spares without much issue, as long as you don't leave them on forever.

Here's a useful tire website. There are many more if you want to Google. Good luck!

http://www.tirerack.com/tires/index_r.j ... 3528673928&

[jessef]

Also take into consideration the tires on there may be past their lifespan eventhough they may look new from the outside.

Possible outcomes are blown sidewall, belt seperation and rubber deterioaration.

I posted a thread about old tires, specifically used one's from Japan.

Echo above comments.

Buy 4 tires.

$200-300 difference between buying 2 or 4.

Sorry to be brutally honest, but is yours and passengers lives worth that amount ?

[FalcoColumbarius]

Ditto. Get four new tyres, don't screw around with peoples lives, neither the people you are carrying in your van or the people in the vehicles around you when you drive. Your van weighs two tonnes and more ~ you blow a tyre on a crowded freeway and people are going to get hurt. Imagine a projectile coming directly at you as you sit in your van. This projectile weighs two tonnes and is travelling at 100 KPH.... What are your thoughts as this is happening? Are your wife, kids or friends in the van with you? Everything appears to slow down as you try to take evasive action.... is your reaction time fast enough? Will your tyres respond fast enough?

JFarsang posted a good thread on the age of new tyres, look for it. Make sure that the new tyres you get are not older than two years when you buy them ~ there is a code on the side of the tyre that will tell you when it was made.

I use 235/75R15s... it's a good number to go with if you are not sure. I consider the tyres to be just as important as the brakes & steering, if not more important as both the brakes & steering depend on the tyres. Where your rubber meets the road is your ultimate link to reality.

Falco.

[g_man1972]

Lots of good valuable info here fellas, thanks for the input. And yea, I wasn't planning on hurtling down the high way with an unsafe van, simply trying to see if their was a affoardable, safe and feasable option to be able to keep my two good tires, which obviously there isn't.

So I made my final decision and am going to get 4 new General Grabbers 30 x 9.5 x 15 from a friend of a friend who can get me a decent price. From what I have found on google they sound like a pretty decent tire, good for rain, snow, mud, rocks, ice... pretty much the whole lot. Not much on this site about them other than someone calling them the "dogs dangles" .... I'm thinking thats a good thing, at least I hope so .

Once I get them on i'll drop a line to review them if anyone is interested.

[FalcoColumbarius]

Parting with cash this day in age can be worrisome, to be sure ~ however, when you have them on you will feel better. Just be sure that they are not too old. There have been incidents where tyres over six years old have been known to separate while the people have been driving, resulting in fatalities. This is from a thread that JFarsang posted and I recommend you to find it and read it. This is why I suggested that you make sure that they are not over two years old, really you want to get nothing over one year old.

This is how you tell: On the tyre sidewall are four numbers; the first two tell you the week when they were made; the second two digits refer to the year. Here is an example (week 36/year 07):


I hope this helps you.

Falco.

P.S.: I would be very interested to read a review on the new Grabbers.

[Erebus]

So I made my final decision and am going to get 4 new General Grabbers 30 x 9.5 x 15 from a friend of a friend who can get me a decent price.

Another warning: make sure the tires aren't too big for your rims. Just because a tire is 15" and the rim is 15", doesn't mean it is safe. It might be too tall or too wide. If so, an evasive manoeuvre could result in the tire "rolling" off the rim. Ask the place that is mounting, or ask around.

One of the reasons the 235/75R15 is a popular size is that it is the biggest tire that can safely be put on the stock rim (I can't remember if they are 6" or 6.5" wide).

[g_man1972]

Hi Falco

Good info and something to be aware of for sure. The ones I'm getting are brand spanking new, just getting them ordered in. Very valuable tip to check those dates though, never would have thought of that and I'll make sure I do. I'll give them a review once I get them in about a weeks time and have a little while to put them through their paces.

Thanks too Erebus, the ones I currently have on the front are the same size 30x9.5x15 hence my motivation to get a similar size, kind of concerned now that you mention it though. My rims are 6.5... well I'll just wait till I get them and ask the shop that's going to install them if they have any concerns.

Now that I have made my final decision, can't wait to get my new rubber. I have a week off as well so hopefully I'll be able to take them up to the mountains and give them a decent work out.