Anybody know the tire pressures Ford recommends on the 2004 vans with 245/75/16's? I'm putting Ford's new 16 inch alloy wheels with load E tires on my 1995 E150. Only thing I didn't consider was if that wheel could take the higher pressure, the tires are rated at 80psi max. Ford's website does not give those wheels as an option with that size tire. So i'm a little concerned.

 

Some of the E250's and all of the E350's (except for the duallys) come with the LT245/75R16 LR E tire for 2004. The E-350 recommended inflation is 55 psi front, 80 psi rear. I believe that you can only get the E350 extended van with the 16x7, 8 on 6.5 bolt pattern Alcoa aluminum wheel, which have been around since the mid 90's.

I'm not sure how you are going to fit the 8 lug wheels on the E-150 since it has a 5 lug pattern, unless you are talking about the new for 2004 16x7 aluminum wheels offered on the E150's.

Inflating to 55 psi in the front and 80 psi in the rear will probably be a little overkill for the E150. Max load rating at 80 psi for the LT245/75R16 LRE tire is 3042 lbs. Inflating the tires to this pressure would allow much more load carrying capability than your axle has. You could probably get away with only inflating to 50 psi, in which case the load carrying capability will be around 2205 lbs. The wheel should be able to handle this pressure, and much more for that matter.

Note, if you ever want to see what tire pressures Ford cars and trucks are recommended, stop by your dealer and check the inside of the gas door. Ford now posts usage (not max tire pressure as shown on the tire) on the gas door. They were hoping that this would remind the customer to check tire pressure regularly.

Another note, keep in mind that when you replace tires on your vehicle and change the tire type and especially the tire size, you may be taking chances with the way that the vehicle safely handles. Ford spends up to 3 years developing the OE tires to meet a variety of characteristics, including safe handling. Also be prepared to see some drop in fuel economy and a rougher ride. The LT245's can weigh, on the average, about 10 to 8 lbs more per tire than a P235/75R15 XL tire.

As with all information on this site, use it at your own risk / discretion.

 

Yes i am talking about the 5 lug wheel. Inflating to 50 psi would be fine it gives me at least the load capacity that the original tires were. Rougher ride I can handle, handling is an issue I'm dealing with. I have put coil over shocks on the rear with spring helpers, on the front, reflex shocks and I am looking for a bigger sway bar. What else can I do to stabilize the front? If I inflate to 50 psi on the rear what should the fronts be? Would it not be okay to inflate to higher pressures but not intend to load to there capacity?

What is the load capacity of the axle? The reason I went with the tire and wheel change was because I was having tire wear problems. I saw a deal on these wheels so decided on them but had a hard time finding 235/70/16'sXL (the size ford is using) tires in a brand and price I was willing to purchase, the 245/75/16 E was a much more available size. I realize there is an increased weight with the tires but what is the difference in wheel weight?

 

You can always inflate to higher pressures, as long as you don't exceed the max stamped on the tire sidewall ( in this case 80 psi). But the higher pressure will alter how the tire footprint contacts the road. Typically, higher tire pressures make the footprint more round with more of the load on the center rib of the tread pattern. This is usually better for wet traction, but worse for ride, sometimes worse for treadwear (on the center rib), better for fuel economy and it may hurt dry traction / handling. Lower pressures usually put more of the load on the outside and inside of the tire tread. Which is usually better for dry traction, but again will cause increased wear, but this time on the outside and inside ribs of the tire tread. The auto companies usually try to find a happy medium that will give them a good combination of load carrying capacity along with good ride, traction and wear. They basically want the footprint of the tire to have a nice even load distribution across the tread, unless of course, the nice footprint pressure cannot hold the max load of the vehicle, in which case the nice footprint is sacrificed for load carrying capability.

I say typically because obviously this varies by manufacturer and design. In most cases, the tire companies will design the tire for the typical operating pressure, in your case 80 psi. You could always inflate to 80 psi and try it out for awhile and see if you like it, or you can inflate to 50 psi and try it. They should both carry the max load of the vehicle.

I'm not sure what you can do to stabilize the front, what are the symptoms of the problem? Keep in mind that you are driving a van not a Mustang.

If you are having tire wear problems, changing tire size won't necessarily cure the problem. If your alignment is in spec and the inflation pressures are right, it should cut down on your wear problems. Also realize that the front suspension design on these vans puts the tires through a huge change in camber as the suspension flexes during compression and rebound. When the suspension is compressed, the tire has negative camber /-\, when the suspension is rebounding, the tire has positive camber \-/. This drastic change in camber usually results in increased wear on the inside and outside ribs of the tire tread.

As far as axle weight, check the placard on the door jamb, it will give you the GAWR (gross axle weight rating) for the front and rear axles.

The difference in wheel weight will depend on material (steel vs. aluminum) and wheel design. The real only way to know is to weigh them. Typically the 16" should weigh more than the 15" (if they are both aluminum).

 

My wheels now are steel and the 16's are aluminum. My main problem has been cupping on the tires and a vibration. I just replaced all the shocks and found none to be bad. I have been dealing with this problem for quite awhile. I just found out that I was given P rated tires instead of XL's. I specifically asked for XL's and have had problems for two years I kept going back and getting the tires rebalanced and asking them to check things out with no success. I have pretty much ruled out anything that I know of that could be causing the cupping.

I'm beginning to believe that it is an alignment issue because it all began when I first went to NTB (National Tire and Battery) purchased a set of Dunlop Rovers and had them align it, complained about cupping on those tires and got a set of Bridgestone Duelers and began having the cupping again. I have not been anywhere else since. This last time I went to NTB to have a rotation and balance they told me again the tires were cupped. I asked them to check things out and they assured me that they would, I went out to the service bay asked if they could check the ball joints, the guy said I don't know how to do that and all the guys are out to lunch. That along with the the guy taking his time while I'm wanting to get my key and paperwork so I can leave was the last straw.

So now, with some info found on this site I decided to upgrade the tires and head to a different shop to have it aligned and checked out. Do you know of anything other than shocks that could cause cupping? Someone else on this site is certain it is an alignment problem mainly camber.

 

The XL tire is a P rated tire... The size markings read "235/75-25XL" on an XL tire... You will have to recalibrate the speedometer to handle the larger tires, if you don't it will through the shift points off, and make the spedometer read wrong.