Changing stock 17" wheels to 18"

[BON DIA]

We're narrowing in on a '07 SEL Plus...comes with 17" wheels...I like the 18" Painted Premium Al better. Have read I should go for aftermarket wheels, not OEMs. Ok, can do. But what would I have to change to make everything work correctly (speedometer & transmission) if I changed wheels?

 

Thx...P

[akirby]

We're narrowing in on a '07 SEL Plus...comes with 17" wheels...I like the 18" Painted Premium Al better. Have read I should go for aftermarket wheels, not OEMs. Ok, can do. But what would I have to change to make everything work correctly (speedometer & transmission) if I changed wheels?

 

Thx...P

 

Nothing. Just make sure the tires have the same diameter as the OEM tires, or as close as you can get (5% or less should be ok).

[Lex Talionis]

and make sure you get the sensors put in that can read the tire pressure

[solas989]

A reputable tire place will make sure that you +1 Size up correctly. Since the Edge can accept 18" as standard - there will be no issues plus sizing from a 17". Visit tirerack.com for more information if you need it.

 

You can go OEM rims if you want - however for the cost, you could most likely get more bang for buck and personality with aftermarket ones.

 

Definitely get the TPMS monitors installed - or have Ford disable it so it doesn't annoy the daylights out of you. I assume Ford can do that - Mazda does (however this was in 2006 and I think TPMS if required by law now in 2008 models (but you have a 2007 so you might be fine) - can anyone confirm?). It is up to you because TPMS is not really all that effective if you monitor your tires like you are supposed to - it just annoys me on my Mazda - especially since it did sit outside for a few years in the nice cold weather (which compresses air and makes the system think there is less in there than actually is).

 

Good luck and show us pics when done.

 

Solas

[Lex Talionis]

arn't they mostly using mostly nitrogen in tires now as one combat against cold pressure changes as they are less susceptible that way.. or is that just Costco and after-market thing at wheel and tire places?

[solas989]

Not everyone uses N - most still use O (most likely depends on your region I would guess). I still use O because it is most prevalent around here. The only place that uses N here is Tire Discounters - or is it Discount Tire. We have no Costo. I like being able to anywhere to fill up with normal O instead of specifically looking for a place with N.

 

Now if TPMS would show me which tire is low - that would be an improvement. Even better is if it would show me what the tire pressure is at each wheel. That would make me a happy camper.

 

Solas

[akirby]

Not everyone uses N - most still use O (most likely depends on your region I would guess). I like being able to anywhere to fill up with normal O instead of specifically looking for a place with N.

 

Actually you're filling up with mostly N, not O, regardless of where you go. Air is 78% Nitrogen, 21% Oxygen so pure Nitrogen isn't gaining you very much. Racers use it because even 1/4 lb of pressure makes a difference in handling. The biggest benefit of pure Nitrogen isn't the smaller pressure change, it's the fact that it's drier so you have less moisture inside the tire which helps resist rust long term. Might also help with the new pressure sensors.

[Lex Talionis]

Costco guy once told me that N leaks out slower over time versus O - but this could be BS FAIK

[bbf2530]

Costco guy once told me that N leaks out slower over time versus O - but this could be BS FAIK

 

Hi Lex. :D Yes, the Costco tech was correct.

 

Some of the major benefits of Nitrogen are:

1 - It is less affected by temperature variation. Regular compressed air can lose/gain up to 1.5psi per 10*F fall/rise in temperature. Nitrogen does not have this problem.

2 - As akirby stated, Nitrogen does not hold moisture as compressed air does, so it can lead to less oxidation/decomposition of the inner structure of the tire.

3 - As you were told, you will see less pressure drop over time, due to the fact that Nitrogen molecules are larger than Oxygen molecules, so they leak less readily. This only applies to incidental leakage, not actual punctures. If you get a puncture, your tire will still leak like a sieve.

 

Downsides are:

1 - Unless you get a "Free Nitrogen Fill" (keeping in mind that there is no free lunch), you are now paying for something you usually can get for free (compressed air).

2 - Once you have a Nitrogen fill, you cannot use regular compressed air to top off a low tire without losing all of the Nitrogen fills benefits. You therefore need to have a shop/Service Station readily available with Nitrogen fill equipment.

 

All of that being said, a pure Nitrogen fill is more "idiot-proof" than compressed air. However, a smart vehicle owner will still need to check their tires as religiously as before.

 

In addition, the TPMS systems are calibrated to warn you once the tire pressure has dropped 25% below the "Manufacturers Recommended Pressure". I believe the psi "recommendation" for the Edge is 34psi. That means you will not even get a warning until the psi in your tires has fallen below 25.5psi. That is already well into dangerously low, possible catastrophic tire failure at high speed levels.

 

I check my tires often, so feel no need for the Nitrogen fill (maybe I'm just cheap? ). For those who are a little more lax on vehicle maintenance, I can see how the Nitrogen fill could have benefits. Just understand that the new TPMS systems and a Nitrogen fill do not make your tires maintenance free and idiot proof.

 

And contrary to some well intentioned but incorrect information that has been posted in the past (not in this thread, but by other members in other threads), Nitrogen will not improve the ride/handling or MPG's of any vehicle, assuming that we compare apples to apples (two vehicles, one Nitrogen fill, one Compressed Air filled, with the proper psi in their tires). In other words, 34psi of Compressed air will give the exact same MPG's and ride/handling as 34psi of Nitrogen.

 

Whatever everyone decides to do, I wish them the best of luck! :beerchug:

Edited February 15, 2008 by bbf2530

[solas989]

Well said bbf!

 

Is that really true that it is 25% now - on my 2005 Mazda 3 - the recommended pressure is 32 - at 29 it beeps at me. If it really is true at 25.5, that is sad. I still check every week at fill up - takes 3 minutes to prevent an accident or more costly repairs.

 

Good Luck

 

Solas

[bbf2530]

Well said bbf!

 

Is that really true that it is 25% now - on my 2005 Mazda 3 - the recommended pressure is 32 - at 29 it beeps at me. If it really is true at 25.5, that is sad. I still check every week at fill up - takes 3 minutes to prevent an accident or more costly repairs.

 

Good Luck

 

Solas

 

Hi Solas. :D The laws pertaining to the requirements of TPMS on new vehicles state that it must give a warning at no lower than a 25% drop below the "Manufacturers Minimum Recommendation". That is the minimum sensitivity requirement set by law. Of course, that does not mean that a Manufacturer cannot have a system that will give an earlier warning.

 

Then we have to take all of the other variables into account, margin of error of the particular system in each vehicle, variations between the accuracy of your tire pressure gauge and the actual true psi reading, variations between when each reading was taken, etc etc.

 

If your TPMS system is truly that accurate, and your tire gauge is also giving you an accurate reading, I would consider myself lucky that it warns at that little of a loss. It actually is warning you at approximately a 10% loss of pressure (32psi X .90 = 28.8psi). I would rather have that than a 25% loss warning.

 

Also, keep in mind that the 25% loss warning requirement is based on "Recommended Pressure" for the individual vehicle. So if your Mazda's recommended pressure is 32psi, a 25% loss would bring you down to 24psi (32psi X .75 = 24psi, not 25.5). Even lower than you expected, and that much more dangerous.

 

The TPMS systems serve a useful function, but nothing can beat proper preventative maintenance. They are the equivalent of what some call an "Idiot light". When that warning light comes on, it is saying the equivalent of "Hey dumbass, when is the last time you checked your tires, they are low".

 

Of course, I am half joking with the above statement, as I realize a properly functioning TPMS system can also perform a useful function by warning of a puncture/leak/air loss that could have occurred while we are driving, no matter how religiously we may actually check our tires. :yup:

 

Anyway, you are doing the smart thing by regularly checking your tire pressure yourself.

 

I hope this information was not too confusing.

 

Good luck! :beerchug:

Edited February 15, 2008 by bbf2530

[druck52]

We have noticed the low tire lights coming on at work with tires at 30psi when factory recommends 35psi. Those lights don't seem to help much though because people still don't check there tire pressures. They bring them in for a warrenty repair becuase something is wrong becuase there light is on, it drives us nuts. Also nitrogen may loose air slower but they still go down. Alot of people thing they don't have to check there tires because they have nitrogen. Sorry for the rant, it just is such a pain in the butt. If people checked there tire pressures like they are supposed to we wouldn't need those stupid lights.