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  • Need the right tire size for unusual setup

    I just picked up a 1994 MkVIII for a good price. It had been sitting for 2 years since it had the tranny dip stick leak. That's fixed along with all of the other neglected fluids and such. It runs great. But now I have two problems The first is a message center and gas gauge issue that I will post on the electrical area. It does need new front suspension too since it leaks down over night. I'll probably convert it.
    The second is tires since they are obviously bad from sitting. The PO had a strange setup on the car. I think that he wanted it to look like a drag car. The front tires are now 225/45/18 on 18 x 8 rims. The rear tires are 245/35/20 on 20 x 9 rims. I'm sure that I could run 255/35/20 on the back, but what to run on the front. 255/45/18 would exactly match the rears for diameter, but will they rub without messing with the fenders. I could also go with 245/45/18, but they are just a bit less tall. What's the feeling on the best tire size to run on the front. I am considering the Barum Bravuris 3HM tires since the price on them is good.
    And yes, it would be nice to go matching wheel size, probably 18s all around, but I can't afford that now.
    Bill W

  • #2
    After further examination, it appears that they are 18 x 7.5 on the front and 20 x 8.5 on the rear. They are Bentchi B14 wheels and they do look good, but they are not exactly size matched. Both front and rear tires look too narrow for the rims.
    Bill W

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    • #3
      A further wrinkle appears in the front tire situation. The passenger side, which has failed, was a 225/45/18 while the drivers side has a 215/45/18 on it. But, while looking at tire specs, I think that I may have answered my own question. The widest tire that the 18 x 7.5 rims will properly support is the 245/45/18. The offset on it is 38mm and I think that it will be good since it has plenty of clearance to the fender now.
      The wider rears will support the 255/35/20, but I'm concerned about the basic issue of the offset on the rear wheel. It is 35mm which pushes the rim 23mm outward from stock. It does not appear that the current tires are hitting the fender, but they are at the edge of the inner fender lip. I don't know how much travel the rear suspension has to determine if this is a potential problem. Are there suspension stops or does the shock just bottom out? Does the travel stop below the fender rim? I'm not thinking of lowering because of the hideous condition of AZ's roads.
      Bill W
      Last edited by ranchodenieve; 09-25-2017, 12:28 PM.

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      • #4
        While I'm about as far a thing from a wheel/tire expert as we have here, it sounds like you have a few concerns worth addressing.

        The first thing to be aware of, is that if the air suspension either fails, or is manually adjusted, it is well within the suspension's ability to "tuck" the wheels inside the fenders under normal conditions.

        If I'm reading your description right, this would cause clearance issues for you in the back right now, but not the front. If you plan to switch to springs, this is obviously less of a concern.

        If you have to prioritize, and not fix it all at once, get your front tires sorted. (matched) and hope that the back holds together long enough for you to address it in the future. Or see if you can find an OEM set of wheels for cheap, and "start over." I don't feel like you're totally in love with the current configuration. You have to be happy with it, or it will be a source of frustration forever.
        Mike Martin

        1997 Mark VIII LSC 5.0
        2001 Dodge Dakota

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        • #5
          Yet another issue has appeared. It seems that the passenger rear wheel has a dented bead area inside and the front passenger wheel has minor ding too. So, it looks like new wheels are in the future now. I'm thinking 18 x 7.5 or more likely 18 x 8. What is a good offset to run with these sizes? It appears that many of the 18 x 8 wheels that are commonly available have 40mm offset that seems too high. Can I run 255/45/18 without rubbing on the proper offset 18 x 8 wheels or should I stick to 245/45/18 on 18 x 7.5 wheels?
          Bill W

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          • #6
            18x8, +36 offset or so. there is a little leeway there.
            245 45 18 tires.
            1996 Lincoln Mark VIII LSC Opal Opalescent on grey, 276/287
            1995 Lincoln Mark VIII LSC Indigo Lights on black
            2002 Ford Focus SVT Sonic Blue on black

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            • #7
              Where does one find these wheels. The few that I've seen are down right ugllly
              Bill W

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              • #8
                I decided to go with the wheel set that I have now for a while. I found someone in Tucson who can fix the wheel dents in the bead area. They said that this was pretty minor and easily fixed. It's a lot cheaper than new wheels and they've been doing this for 17 years. But, as I was removing them another interesting issue appeared. The PO apparently used the wrong lug nuts on it. 1/2 -20 instead of 12mm. Fortunately, the wheels didn't fall off. Also, fortunately, the lugs are all in good shape since he used really cheap lug nuts that deformed on the threads inside without damaging the lugs. How can you be that dumb, but some web sites seem to put up both sizes on a lug nut search. So, now I'm just waiting for the repair and then the tires to arrive since they don't stock the ones that I need on the rear wheels.
                The next issue to solve is the spare tire problem. It has no spare tire now. I can get a 16 x 6.5 steel rim for cheap along with the stock 225/60/16 tire. But, I think that it probably won't fit in the spare tire bay without protruding into the trunk. What do people do for a spare? I do hate those fake spares. I don't see any other combination that's close to the tires that I will be using. I guess that I might just have to live with the spare sticking up into the trunk. Any ideas?
                Bill W

                Comment


                • #9
                  I'm glad to hear you've got your rim/tire situation sorted. Hopefully those repairs serve you well, and I'm glad you discovered the lug nut problem before it was too late!!

                  As for the spare, I'd be tempted to keep your eyes open for an OEM mini-spare, like it had originally. (salvage yard, this website, etc..) It's not elegant, but it will get you down the road in a pinch, and fit properly in the trunk..
                  Mike Martin

                  1997 Mark VIII LSC 5.0
                  2001 Dodge Dakota

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                  • #10
                    I have a spare you can have, they no longer fit on my car.
                    Eric
                    -00 Honda Accord (The MPG'er)
                    -97 Mark VIII Base (The Row'er)
                    -95 Mark VIII LSC (The Go'er)
                    -14 Model T touring (The Show'er)
                    -Rebuilding the T

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                    • #11
                      The tire saga continues. The rims are fixed and they look great. Apparently the rear tires are not a very common size. They only have Nittos in stock. Over the past 2 weeks, my tire dealer has tried to get the Barums out of their other stores in California. Each time, the shops blew off shipping them and then sold them. So, my local store decided to offer me Cooper CS5 Ultra Touring tires for $20 more than the Barums. A really good deal since they actually want $175 more for them. But, they still had to order them. However, this time they are coming from the Cooper warehouse directly. I'll actually get them. And they come with a $70 rebate from Cooper. So, next week it'll be on the road. The wait turned out to worthwhile.
                      Bill W

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                      • #12
                        Hi Eric
                        Thanks for the offer of the spare. I think that I'm probably just going to have to live with a full sized spare sticking up into the trunk though because of where I live. I'm in Tucson. Some road trips take you miles from civilization where tires are available. If your tires die in Desert Center, you are miles from any where that you could get a replacement and a fake spare wouldn't last long enough to get you there. It's the only gas for 100+ miles and the restrooms are beyond gross, but you have little choice, but to stop there and pay a small fortune for gas. And crossing into west Texas is even worse.
                        Thanks
                        Bill W

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                        • #13
                          That's a great update on the tires, Bill I look forward to hearing your review of the CS5. I've had good luck with Cooper in the past, so I suspect you'll be pleased with them.

                          I absolutely get what you mean about failures in the middle of the desert. I've been fortunate on my trips through the empty parts of the western states. If that's your life though, it pays to be prepared.
                          Mike Martin

                          1997 Mark VIII LSC 5.0
                          2001 Dodge Dakota

                          Comment


                          • #14
                            The tires arrived on Wednesday. I put them on yesterday. It really runs nicely and feels good except for the rear shocks. The tower is toast and so are the shocks. But, a new wrinkle has appeared. It used to slam down in the front overnight with the old tires on it. The rear stayed up. It didn't leak down while it was up in the air for 3 weeks waiting for the tires with the air ride off. Then, it didn't leak down overnight with new tires either with the air ride on. Maybe, the air ride is still good. I'm wondering if the too small mismatched front tires were the culprit. It had a 215 on one side and a 225 on the other and were much shorter than the rear ones. Was it trying to level and just couldn't get there and simply dropped as far it could trying to level something that couldn't be leveled. The new tires match almost perfectly in height in the front and rear. I'm going to wait and see if it stays stable before messing with the front end.
                            It made it through the emissions test with really low numbers too.
                            Bill W

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                            • #15
                              Sounds good!
                              JP

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