Tires, tires, tires

the_big_al

Probably not a whole lot. I would get it corrected as soon as you get the chance but for the most part it should be okay.

the_big_al

Rotation scheduling aside - why not find a shop that will do a lifetime rotate and balance? Since I have been away for three days, I have yet to make it through all the new posts so this may have already been said but....

That way you can have the tires rotated as often as needed and not have to worry about paying each time. Several shops should offer it and so should the shop that you bought the tires from, unless they are the tires that were on the car when you bought it.

the_big_al

HEY CANUFIXIT! Good to see you in the tire forum too. I used to be a service manager at a tire center so I frequent here as much as Ifrequent the S-10 forum... So you got the Toyos? I hope they work well for you . Anyway, from what you say, I would agree with micweb, although maybe before paying to have it balanced that way, take it back to the shop and have them re-balance. Sometimes, especially with an aggressive tire like the Toyo's they can be a little more difficult to balance. Also find out it how much wieght each wheel/tire combo is taking. That could be a factor in the balancing. If need be they can rotate the tire around the rim to maybe have it balance better. It might be a wheel issuse, but doubtful since you didn't seem to have the problem prior to the new tires. You will hear more noise with the new tires compared to the old since the tire is aggressive and you have large unworn treadblocks hitting the pavement instead of worn out tires hitting the pavement, but you should not really be feeling a vibration.

the_big_al

Don't let the dealer do the work unless they will do it for less than 60 some odd bucks, but then again, if you trust the dealer and they are a little more expensive than I wouldn't mind paying. I pay my mechanic 60 bucks to do an alignment and for me that is a little pricey. But I pay the price because he is an excellant mechanic and does really good work. For that I don't mind paying a little bit extra. (An alignment here costs between 40-60 bucks).

I would recomend you wait until after you get the new tires. Then immediatly take after, either have the tire shop you buy the tires from do the alignment if they are able; some will offer lifetime alignments and might throw it in with a tire purchase, or at least discount it. If the tire shop doesn't do alignments then ask them for a recomendation if you don't know of a good place. Or you can take it back to the dealer, but like I said before only if they have a reasonable price.

Reason for doing it after you get the new tires is so that the aligment can more accuratly be done. If the tires are severly worn, or worn unevenly, it could possibly throw the alignment off when new tires are put on.

the_big_al

Yes - take it to your trusted tire shop. My best guess is that there is a nail in it somewhere. Easy to fix. If it does turn out to be a nail, make sure they use a plug patch. Make a solid good repair.

It is also possible that you could have a bead leak where the tire leaks from between the tire and the rim. If the tire shop can't find anything in the tire, have them clean the rim edge, then rim the tire bead with bead sealer. that should solve the problem.

the_big_al

ha - I thought those types of plugs were illegal? I have always when I used to do tire repairs used a plug patch combo where the plug and the patch were a single unit. Done from the inside, I would drill out the hole made by the nail to make it big enough for the plug, than clean and buff the inside of the tire and glue it and then plug patch it... very very rarely had one fail.

the_big_al

Okay - you need to handle rainy, potholed streets. Stay away from a larger rim. More rim, less tire to absorb the shock and blammo! One hit in a pot hole and there goes your new rim. Sorry. Large rims may look flashy but they ain't all that practical in most applications, especially in your 96 Honda.

My recomendation is to stick with the 15" rims that came with the car. If I remember correctly that particular model of car with 15"'s came with 205/60r15 tires. It could have been a 195/65r15. I don't recall off the top of my head and it could also vary depending on what line you have - LX, EX or DX.

What are your needs besides needing to handle wet roads? How often does it rain? What is your driving style? There are several tires out there and some might be better at dry traction, giving you the ability to corner better and give better braking and acceleration. But they will not last as long as a tire more suited to longer life and less "spirited" driving. Other tires are designed to really be able to manage wet roads. If you are wet roads a lot I might recomend one of those tires....

Here are some options:

BFG Traction T/A - An all-season performance oriented tire. It should do okay on wet roads and has fairly good dry traction. The wear is iffy. Depending on how you drive it could last several thousand miles or less than 40K.

Goodyear Assurance Triple Tread - I don't know a lot about this tire but it is highly rated and from those I have talked to that have run it and the reviews I have read it is one of the best for wet weather.

Michillen Symmetry - I am not a fan of Michellins, but others swear by them. I am not saying it is a bad tire, but I think it is a little pricey and you can get the same or better performance for less money. That said, this is an excellant tire in the Michillen line. I have put several of these sets on Hondas. From Accords to Oddesys. Has a comfortable ride, good traction and able to handle wet weather. But a little pricey and from my experience, not long lasting. You might get 50K out of this tire.

Douglas Touring - Available at Wal-mart only. This is the tire I would choos. Economical, wears good and gives good performance. I would feel confident that in the 195/65r15, or you can step up to the 205/60r15 (a little more sturdy, wider tire), that this tire would meet your needs provided you aren't a speed racer.

I have given you some basics. There are a ton of tires out there from other manufacturers. Kumho, Firestone, Bridgestone, Dunlop, Uniroyal, Continental. I would stick to something from BFG or Goodyear, but Kumho also makes good tires, although in the sizes you need I have never had experience with Kumho's. Continental's are not a bad choice. Firstone if you can get past the "Ford Stigma" has some good choices...

So I don't think I helped much, but muddied the waters with a whole bunch of choices

Short and simple recomendation - Wal-mart Douglas Touring. Stay with the 15" rims.

the_big_al

when reading reviews, I tend to look more for the reviews that are reviewing tires with at least 20K on them or more. The more miles the better. But you have to still be careful. I have found that Tire Rack's reviews can sometimes be skewed and not entirely accurate, although on mostof the sets of tires that I have bought, the reviews have been fairly accurate.

I have never purchased from Tire Rack, but have used the site extensively to find tires that would work for my vehicles and then bought them at a local tire shop. In all cases I have spent about the same once all the costs are added in, but most important to me is I have saved time.

the_big_al

Sam's Club is a good place for tires. They should have very competitive prices. The service if it is anything like it's sister at Wal-mart could tend to suffer, but since I have never been to a Sam's Club for tires I don't know. But as far as I know they only do tires. Nothing else. Good and bad. Nothing else will get pushed on you, but if something like a wheel stud breaks or is stripped, or an alignment is needed, than you have to go to a different shop.

the_big_al

I used to work at Wal-mart Tire and Lube Express and it seems to me that i don't remember "honoring" Sam's Club tires. But then there was not a Sam's Club in town so I don't even remembering that issue come up. However, if it was a Wal-mart Specific tire than it was a no question's asked, just take care of the tire. That didn't mean the customer automatically got a free tire, it just meant to take care to the tire according to Wal-mart's warranty. Wal-mart for some reason sells it's warranty separate. There were people that would come in and just want a tire. No balance, no new valve stem, just a tire mounted on a rim. But 99% of the time the warranty was included and so to save hassle of someone having to find their paperwork to prove they bought the tire warranty, I just assumed the warranty was in place. Now if a customer had special ordered tires, unless he or she has been a repeat customer, than I generally asked to see the tire paperwork to verify the warranty and mileage and such.

the_big_al

I wouldn't be surprised... I have run a set of Kumho's before and really liked them... They were however a little more expensive than the normal Kumho, but at the same time it was also an odd size and Kumho beat the other two tire manufacturerers that also made that particular size... One was a Pirelli and the other a General.

the_big_al

I would recomend the Kumho. I have run a set of the Ecsta on my truck (an S-10), and while the truck is obviously not designed to handle like your Volvo, it did drastically increase it ability to take mountain curves more confidently. They were not very quiet however, but the price was good. They were also a fairly durable tire for what I put them through. Wet traction was excellant. It rarely rained, but when it did, it would leave puddles big enough to sink a battleship on the road that I traveled on. Because it was out in the country some and I liked to have fun I would hit these puddles as fast as I could for the sheer joy of of it. Prior to the set of Kumho's I had to be extremely careful because the rear end would start to slide out on me and I would start to lose control. With the Kumho's I could hit the water at a good rate and still maintain steering and traction. In that same vein, it was also one of the nutty things I did when it rained that I had to spin my tires going around a corner from a standstill at an intersection. Again prior to the Kumho's it was real easy to set the truck into a sideway's slide/drift. With the Kumho's I could spin the tires all teh way around the corner and the rear stayed planted. I actually found it difficult, unless I was in dirt to kick the rear around. Dry pavement traction was pretty good too. The tires didn't last too long, but that was probably more from the way I drove than anything else.

The Kumho's were relatively inexpensive and performed well. From what I have read, this is true across the Kumho brand. It seems as if Kumho is to tires as Hyundai is to cars. They are an off brand, but put to the test they perform as well or better than many of the major players. I did run the Ecasta STX rather than the ASX, but given what I have read about Kumho's, it should perform well for you.

the_big_al

Well - I can't point you to a source, but I can tell you that I am running a 255/55r 16 tire with a temp rating of A and traction of A. The tire weighs 32 pounds and has a 103T load rating and a speed rating of T. It has a max pressure of 44 pounds. It is a very heavy tire and very stiff sidewalls. Compared to the 235/60 R 16 that I was running it is 5 pounds heavier. The 235/60r 16 also had a rating of A B, 99T load range and T speed rating and a max inflation of 44 PSI.

Now compare that to the 205/75r15 that came stock on the vehicle which weighed in at 24lbs, had a temp/traction rating of B/B, a max inflation of 35 lbs and a load range of 97S. It was also a very flimsy tire. I could sit on it and make it collapes. The 255 I could stand and jump on it and it would hold it shape.

I may be talking out my butt here but it seems that the statement made is not really true - or may be true in some cases, but not in all as I just point out. The 205 had much less material in it and a lower max pressure. Actually, I wouldn't run the 205 at anything less than 35 PSI as it would probably not be able to take the abuse and heat because of how flimsy it was. The 255 and also the 235 on the other hand I would feel safe if the pressure did drop to below 35. I found that the 235 wore best at 32 PSI and the 255 at 35 PSI, but I have run the 255's down as low as 30 for a smoother ride, but gas mileage suffered as well as handling. Anyway, the higher max inflation tire was much heavier than the lower max inflation tire. It was more robust in its design. So to say that a high max tire is cheaper to make and is lighter than a lower max psi tire doesn't make sense....

I doubt I know what I am talking about, but I am trying to make sense. But maybe the best way to really tell is to compare the same sizes and see what kind of load range, temp rating and speed rating you get... That might be better than my varying sizes comparison. Try tirerack.com. They have a couple places on how tires are constructed.

the_big_al

That shouldn't be too much of a problem. The 205/75 15 is narrower, but not by much and the two tires are about the same hieght so it shouldn't cause an issue with the speedometor/odometer.

the_big_al

You can get a set at wal-mart or any other place like Autozone or Checker's. They won't be OEM and the quality will be what you pay for them. THey will last through maybe one or two rotaions until the tire tech gets wheel cover happy and cracks one or snaps a fake lug nut off because he thought it was real and he is careless. Usually these types of wheel covers are built out of cheap plastic that doesn't really hold up well over time.

I think I know that kind you are talking about and it is actually a pretty good, heavy duty well built cover. Like was mentioned before, try the junk yards, or there are online sites that specialize in obtaining "OEM" wheels and covers.

the_big_al

oh come on! Those are the COOLEST! You'd be pimpin' to put those on. Nothing better than a spining wheel cover!

not..... :sick:

the_big_al

The BFG All-terrain is a fairly expensive tire to be using it on the street, with little off-road use and there is probalby a better road tire out there, the BFG is a pretty good tire.

Now if it were the BFG Mud-Terrain, I would say your were nuts, but the All Terrain isn't too bad. Pricey, but it's a good tire.

the_big_al

Not recommended to change the tire size that drastically. It will affect the speedometer and the the odometer as well it could affect the ABS system. If you are going to switch sizes the best thing to do is stay as close as possible, to the OEM tire diameter. If you can't so that, I might suggest looking at a different tire.

The Goodyear Assurance Comfortred or the Goodyear Fortera Tripletred come in the 225/70R16 sizes and might suit your needs.

the_big_al

I know you mentioned you were in Phoenix Az - you might try Discount Tire or heaven forbid (depending on what part of Phoenix) Wal-mart.

Discount was able to get me the tires I wanted (odd sized and brand) for an excellant price and Wal-mart is able to get anything that Goodyear produces via special order. The Wal-marts I used to visit down there were a little lost in the dark when in came to special orders. Having managed a Wal-mart tire center in a former life, I basically had to show them how and where to find the tires in thier books. But they can get them and they can get them for a good price... probably better than the Goodyear dealer.

I would recomend Discount however since they seem more knowledgeable and seem more willing to take better care of you. They might also be more flexable on the price.

the_big_al

They didn't know how to look for them. Why they would be looking in a loose leaf notebook I don't know. Wal-mart has catalogs that are supposed be both behind the counter by the computer they use to write you up and by the tire display. The catalog(s) lists all the sizes and types of of tires that Wal-mart can get.

Now granted it has been a few years since I have worked there, but the process is still basically the same. There is a book for all Michilen tires which includes Uniroyal and BFG, a book for Goodyear, which also includes the Walmart house brand Xtra-Trac and a book for Continental which also includes General Tire.

The basic process is, they look up the tire you want in one of these books. They can also look up the size you need and be able to tell you what tires come in that size. Once you have found what you are looking for, they take that information down and call a 1-800 # to place the order. Depending on where in the country the tires have to come from, it can take as little as 3 days or as long as 10 or so. The 1-800 # also tells them if the tire is in stock, or if it is indeed available. Then depending on store policy (it vaires from store to store), you either pay for the tires right then and there, or it's a pay on install. Once the tires are ordered, you wait for them to call and if they do their job right, they should call you when they come in.

In my case with my last set of tires I ordered (they beat Discount's price by more than $100), I had to walk them through the whole process, including showing them their tire catalog... At first they claimed they couldn't get the tire I was after, but after a couple quick phone calls to a friend of mine who still works in a Wal-mart Tire Center, I was able to confirm that indeed they did and could get the tire I wanted.

That is why I mentioned before that you can go to Wal-mart but heaven forbid. :P

the_big_al

I agree that the Michilen LTX is more of a "truck" tire. You can use it on a Highlander, but I would lean more toward passenger tire my self... The afore mentioned Goodyear Comfortreds come to mind as being a good replacement tire. I think that you'll be happier with the ride and the wear. Michilens in my experience, while a good tire, wear faster than I would like and cost more than I want to pay and ther are brands out there that are just as good for better money.

the_big_al

I might also ask what kind of tires are you going to use? They may or may not use a "quality" tire and you may be stuck with what ever they decide to use whether or not it's what you need or want....

I am not so sure I would want someone else deciding what tire is good for me. I would much rather be able to research and make that decision for myself.

the_big_al

Lot's of good suggestions given here... I would recomend (and this is the setup I have) a small AC run air compressor. They can be had pretty inexpensively at sears or wal-mart and even harbor frieght. One that has a 5 gallon dual or single tank that can store the air. It comes in handy for everything from bike tires to running a nail gun and yes even car tires for when they go flat in the driveway.

But how often does that really happen? Now for the road, you can do a couple of things. A 12V compressor works fine, but like mentioned before, can take some time to pump up when a spare tire might be more beneficial (but then you have to get dirty). So if you have the trunk space, I would say get a small air tank that you fill up with your air compressor at home and carry that in your car along with your 12V compressor. That way if you do get a flat and don't feel like getting dirty with the spare, the tank offers a quick way to get a few pounds into the tire to make it driveable to a service station and the 12V offers the ability to get it up to full pressure and with the combination of both you spend less time on the side of the road.

Although in my opinion, you'll spend far less time just changing to the spare. Then you can throw the flat in the trunk, plug in the compressor and let it fill up the tire while you drive in case you get another flat....

the_big_al

Those torque sticks are designed to keep the morons in the tire bays from over torquing the wheels when they zip them back onto the cars with there 2 speed air guns. OKay so not really two speeds but they seem to think there are only 2 speeds... off and on all the way.

You can sit on the gun with a torques stick and it will not tighten past it's specified torque limit. But then you must go back with a real torque wrench and properly make sure all the lugs are tightened....

the_big_al

yes that is true.... I would hope however that anyone working in a tire shop would already know that, but still good advice for anyone that may end up changing a tire on the side of the road or in their driveway.

the star pattern is the preferred and the way you mentioned is the best way to make sure the wheel goes on straight

the_big_al

I would tend to agree that they are too old and haven't had any use for several years. Ususally you can visibly inspect a tire by looking for weather-checking and "shininess", but I don't think that I would trust a 7 year old tire that had never been used even if it didn't show signs of age.... especially when the replacement cost of those two tires would be relatively inexpensive insurance compared to the cost of the repairs needed if one of the old tires happens to fail.

the_big_al

You probably only need 4 new tires. The wheels are probably only cosmetic damage and unless they bother you, I wouldn't bother replacing them. It will be less expensive as the size tire you need is fairly inexpensive. Unfortunately however, that particular size is not very common so there isn't a lot of choice when it comes to tire selection. But there are a couple of good choices out there. The BF Goodrich Traction T/A is one that I know of.

I would recomend finding a good independent tire dealer and taking the car there. Since I don't know where you are located at I don't know of a good one to send you. If there is a Big O Tires, or Discount Tire near you those are good places. Wal-mart is also a decent choice, but they might not have the size you need (I know a buddy of mine had that same size on his Neon and wasn't able to get tires there. This was in 2002 though so that may have changed?).

The tire rep at the tire dealer should know what you need and be get you into a good set of tires. As for the wheels, don't replace them yet. After you get the new set of tires, keep a close eye on them and see how well they hold air. If they seem to have a problem holding air, it could be that you have a defective rim(s), which could be related to them being scratched, etched and pitted after so short a time period. Of course they could also be scratched, pitted and etched because of road salt and brake dust that has never been washed of either.

But do the tires first. Get some good safe rubber underneath your car so that it is safer on the road.

the_big_al

Goodyear I think? I have actually never stopped to think about where the tires I buy are made. I just buy the tire that suits my needs best, rather than buy the tire that is made here in the U.S. If a tire that is made in Canada meets my needs better than a tire that was made in the U.S. I think I would rather have the Canadian made tire.

the_big_al

well, not too much you can do about it now, except drive the daylights out of them so you have to replace them sooner, but if you want to find out they are good or not, check some of the reviews at tirerack.com for that tire. I take tire rack with half a grain of salt, because a lot of the reviews don't give you much info and also the review was given right after buying the tire when it feels a hundred times better than the old one...

I look for the reviews that have several thousand miles on them to get an idea of what the tire will be like duing it's life.

the_big_al

Actually, the info needed is the current tire size that is on the vehicle. Which you stated is a 16", but there is a lot more to it than just that. I am assuming a lot here and looked up what a 2wd 16" Vibe came with as OE and more than likely is a 205/55r16 tire size.

So having said that, I will recomend some tires, but you will need to go out to your vehicle to confirm that this is the correct size. You will need to look at the sidewall to get that info and then on a door placard to verify that the tire on the vehicle is the correct size. When looking at the side wall of the tire, you are looking for the numbers 205 55 R 16 or some variation. This will give you the tire size. The placard you are looking for is generally located on the jamb of the drivers door. Sometimes it's on a passenger door, or I have also seen in located on the underside of the trunklid.

Visit www.tirerack.com and it will give you a ton of info that would be helpful in learning about how and why tires are sized and etc etc... It will also list a ton of tires in the size you are looking for. I would recomend taking a look at this site and then coming back here once you have found a tire that looks good and see if anyone here has had good luck with them. The tires I have like have been Kumho's, BFG traction series and KDWS tires....

the_big_al

Yes the BFG Traction T/A is a good tire - provided you get the directional one. It's not a very expensive tire and should serve well. I too have heard good things about the Goodyear Tripletreds, but they are a bit pricey for my tastes. I think you would get just as good of performance from the BFGs. I don't know much about the other 3 you mentioned, although I am not a fan of the Bridgstone brand.

the_big_al

it's not unusual for the wheels to need to be re-torqued several miles after a rotation. Some shops even have disclaimers that say you must return after a set number of miles (50 miles or so) to have the wheels re-torqued. I usually thought this was thier way of getting out of a "wheel fall off claim", but I have found that the wheels can seat just a little bit after being driven on thus requiring them to be torqued back down.

When I do my rotations, or I have the wheels off my vehicles for brakes or any other reason, I make sure I get all the lugs all the way on and as tight as I can by hand before lowering the wheel(s) to the ground. And when I do lower the wheel, I only lower it enough to put pressure to keep the tire from spinning while I I torque them. The keeps the wheel straight and true to the hub and lessens the chance that it will seat further after being driven, although I have found that I will have to re-torque everyonce in a while a few ft lbs after several miles....

the_big_al

I'll bet it's the valve stem as well... a loose core or a crack in it. Two pounds a week isn't much and would be hard to detect. What the guys at Big O need to do is pump the pressure up to around 50 PSI (don't worry, the tire can handle it, just don't drive on it like that ) and then put it in their dunk tank hopefully full of soapy water. They should have one. Leave the cap off the valve stem and go very slowly and take their time. The air bubbles coming out of the tire will be very very minimal on a 2 lb per week loss, but they should be there...

EDIT -- Looks like I got beaten to the punch a little bit :P. I didn't read through all the posts before replying. imidazol has the right idea, although I would still pump the tire up several pounds to increase the pressure, therefore increasing the rate of bubble escape... and I would almost recomend doing it yourself if you don't mind getting dirty because imidazol is right. The tire guys (especially at places like Big O) aren't particularly the sharpest crayon in the box. Not that they are all bad, but generally speaking the turnover is high and the rate of edumacation is low. They may not take the time or know what to look for and be more worried about selling $500 worth of tires than spending 1 hr doing a $20 flat.

oldfarmer50

Have any of you increased your tire pressure to get better milage?

I recently went from 32psi (mfg. recommended) to 35psi. The ride is a little firmer and handling seems a tad better.

I wonder if this will really have an effect on milage or tire wear.

Any guesses?

ruking1

Yes. Goverment figures indicate 03 VW Jetta TDI, "NEW EPA" of 35-44 mpg 38 mpg combined. link title

New car sticker EPA 42/49, normal commute 48-52 mpg, full range has been 44-62 mpg. I can get that range (given conditions) @ will. Typically in all around driving 50 mpg. My swag is if I drove it like my Civic, more like 52-55 mpg

But do oem tires with 108,000 miles qualify as an effect on mileage and/or tire wear? They still look good to go for at least another 10,000 oem recommended rotation cycle @ 110,000 miles (will check again at 120,000 miles.) :shades:

Oem psi recommendations are 26 psi on a 44 psi max side wall tire (GY LS-H-crappiest tire of the three that comes oem according to posters @ www.tdiclub.com).

The tires have been consistently run on 38-36 psi fronts, 38-34 psi rears. (the 2 psi ranges are so I can ignore reading the TP for @ least 2 months @ a time. The -2 psi in the rear is to maintain the oversteer characteristic designed /built into the vehicle by the oem.DEAD even wear across the tread width. Alignment was done @ 105,000 miles, but was not needed. Since it was on the alignment rack, it was set back to "zero" (check it/leave it adjust it-same discounted price) . My swag it could have seen another 100,000 miles (for a min of 200,000 miles unadjusted on factory alignment).

Am I guessing?

oldfarmer50

Are you answering my question or someone else's? :confuse:

ruking1

If the technical details are problematic, how can I better answer your questions?

oldfarmer50

"...If the technical details are problematic..."

Yea, I guess you lost me with all the information. Very comprehensive explanation.

If I'm understanding you correctly, you boosted your psi substantially over oem and got much better milage and better (108K miles, wow!) tread life.

Are you an engineer? My father used to explain things like you do and he was one.

ruking1

..."If I'm understanding you correctly, you boosted your psi substantially over oem and got much better mileage and better (108K miles, wow!) tread life. "...

That is correct. While I do not abuse the vehicle, I really run it (TDI=diesel) as a diesel should be run.

I sent both my daughters (after app 1 year of driving under foot, after getting their licenses) to the local speedway to take (Jim Russell's) highway survival course. Among other things they teach; donuts, (yes they had a former (cop) instructor who taught cops pursuit driving) higher speed evasive maneuvers, slaloms for time, higher speed braking (with/without ABS),skid recovery.

The upshot, tires used on the vehicles (4 door Japanese compacts) day to day in this calculated abuse had higher PSI in the tires. So where I use 38/36 they used slightly higher @ 39/40 psi. They do use tires (Yokohama if interested) like you and I would buy.

oldfarmer50

"...they used slightly higher @39/40 psi..."

I always thought that if you raised the pressure that high your tires would wear out in the middle. Guess not.

Why do car makers recommend such low pressures? Do they think a little softer ride is worth replacing tires twice as often? With today's fuel prices I would think they would be telling everybody to pump up their tires. What a cheap way to improve EPA ratings. Just test at 40psi.

ruking1

When you read the tires' oem recommendations, they always tell you to follow the vehicles oem recommendations for tires (PSI) !!!!

So really the ones that manufacturer the tires will literally make NO committment! They will say don't under inflate, over inflate, etc etc yada yada. The other thing is that while most all of us ASSUME any tire you use to REPLACE the oem provided tires, should take the SAME PSI, the truth is that is purely an ASSUMPTION !!!! So for example it is common knowledge that when one drifts from the (lousy) oem provided tires there is almost always a decrease in fuel mpg.

So take my example, for example. It is a 195/65/15 H rated tire. 360 UTOQ. 44 psi max tire wall pressure. oem recommendation is at 26 psi. Does that mean 21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44 are WRONG?

Given 26 psi recommendations what is under/over inflated?Indeed what is "correct"? Confusing might be a polite term.

Mr_Shiftright

I'm rather skeptical that inflating your tires say 5 psi higher will have any measurable effect on mileage; however, having seriously DE-flated tires will affect your mileage.

ruking1

Same air, same 5# delta!!?? What laws say it works one way and NOT the other?

Indeed given the example what is wrong with say filling the tires with 44-41 psi and letting it adjust (aka ignoring it) till it gets down to the OEM recommended 26 psi??? So the practical aspect is you can ignore it for (-1# per month) for 18 months!! :lemon: OR... why not ignore it for 5 more months down to 21 psi (-5#'s off oem recommendations?

As a counter point while I am at 108,000 miles on the oem tires and they still looks good to go to a min of 121,000 miles @ 38-36 psi and 38-34 psi, what is the ABSOLUTE min PSI I can run and still duplicate these miles!?? :shades:

Mr_Shiftright

Well that's a very good question and forces me to think it out---i think my impression would be that a seriously deflated tire would have both higher heat and frictional forces (squishy, causing drag).

I do know, for instance, that misalignment will drag the tire and decrease mileage a healthy amount, so a very soft tire might logically do the same.

My two cents anyway.

ruking1

..."Well that's a very good question and forces me to think it out---i think my impression would be that a seriously deflated tire would have both higher heat and frictional forces (squishy, causing drag)."...

In fact the above is the VERY reason why I put what I put!!?? (its more technical than that, but...) So it would seem we are NOT in disagreement!?

jipster

Well, finally got the MPV back into Big O Tires to have them take a second look at the slow leak. Still losing 1-3 pounds a week.

Looks like my slow leak problem is cured. I lost 2 psi riding down to Florida, coming back I didn't lose any... don't know what's up with that. But, the past 3 weeks I've only lost about 3/4th's a pound.

obyone

Must've been that special tar they use on the roads in Florida. :shades:

Or maybe it was that burnt rubber deskman left on the road while test driving that Challenger.

Either way glad it's cured. Well significantly slowed anyway.

capriracer

Try this link:

http://www.geocities.com/barrystiretech/rrvspress.gif

This is a graph of a tire's rolling resistance at constant load and only the inflation pressure is varied. It shows that increasing inflation pressure reduces a tire's rolling resistance - AND that the effect diminishes as the pressure goes up.

ruking1

Since the PSI documentation stops @ 40 psi, it would be interesting to graphically see the "effect diminishing" @ 41,42,43,44 (which is the max sidewall pressure for a majority of passenger tires) & beyond if applicable, i.e., some tires have 51 psi max sidewall pressures.

So if I can extrapolate from your posted graph/graphic, I can go up to 40 psi for the lowest rolling resistance. The reason why I use 38 psi is on the example machine much over this is too hard for my SOTP's feeling. But I do graphically see that 2 more PSI (40 psi) has the lowest rolling resistance.

capriracer

You should have also noticed that the effect diminishes. In other words, the change from 36 to 40 is much smaller than the change from 24 to 28.