Advice On Replacement Tires - Page 3

SheepShagger · 09-29-2010, 10:37 AM

Quote:

Originally Posted by EMrider

Thanks, that helps me understand the concept. Max psi is not necessary the recommended or ideal psi for all situations.

With the SMB, I'm always pretty close to max GVW. For that reason, I've tended to inflate my tires to 75-80psi for most highway driving.

R

Running MAX psi is far more desirable than a psi that's too low, and apart from bad tire wear there really is no disadvantage to it on a heavy vehicle like the SMB (that I know of). Comes more into play on sports cars where you want maximum traction.

This started as I was just trying to show the OP the difference between his two tire choices on the PSI. IE, that all things being equal, he would be running the 295's tires at a lower psi than the 205 tires, even though the 295's can take a higher PSI & Load.

Ozrockrat · 09-29-2010, 02:32 PM

Quote:

Originally Posted by SheepShagger

To do it correctly, you should inflate tires while cold to a figure. Drive to bring the tires up to temp, if the PSI increase is 3~4psi your starting / cold PSI is correct. If it's more than 4psi, your starting/cold psi is too low, if it's less than 3psi your starting/cold psi is too high.
The 3~4psi may be wrong, but it's something like that.

The method we used on mining equipment (where a tire can cost upward of $20,000) was to monitor the temperature. The idea was to fill the tire cold (ambient temp for where ever you are) and then monitor any temperature buildup. On our haul trucks up to 7 degrees C was acceptable over that and the tire was under inflated. If the temp went down or stayed at 0 difference you were over inflated. Not sure on those figures and they will be depend on the tire but that was the principle.

Interesting article on tire pressures. http://www.drivetosurvive.org/tire_safety_article.htm

Jeffrey · 09-29-2010, 02:46 PM

One time I brought my land rover disco in for a service, and some inexperienced guy decided to do ma a favor and fill my tires to the max and not tell me. On the drive home, I actually thought someone there had replaced my shocks with straight steel bars. Nearly broke my teeth.

stikine · 10-17-2010, 08:50 AM

Went into my local Costco, just to inquiry about the cost of replacing my BFG AT 315/70 17 D tires. The tech. asked what the tires were going to go on and I stated a E350, he then looked it up on the computer and said they couldn't install them - he said they only could install an E rated tire on the E350s because of the weight.

What surprises me is that D rated tires are what came on the SMB and I still think with the 4x4 option that SMB west is still installing these tire, even though they are only D rated?

scatter · 10-17-2010, 10:35 AM

Yeah Costco will only install tires to match what's on your door sticker or their computer. They had by far the best price for me so I took my floor jack and air wrench to their parking lot and rolled the old tires and wheels in to them. They mounted and balance the tires I wanted and I put 'em on in their parking lot. Took a little time, but I got what I wanted at a great price.

Ford_6L_E350 · 10-17-2010, 10:42 AM

When Salem-Kroger upgraded my van to 4wd, they put a new ID plate that lists the new tire size. Costco can deal with that.

Doesn't SMB do somethng similar?

Mike

**BroncoHauler** · 10-17-2010, 12:11 PM

Go with E rated. Personally I do think SMB should steer people (mandate?) E-rated tires on all their conversions. I think D-rated tires are at the edge of safety for a fully converted van.

I found my van handled better with the E-rated tires too.

Herb

woodbee · 10-17-2010, 02:57 PM

Quote:

Originally Posted by BroncoHauler

Go with E rated. Personally I do think SMB should steer people (mandate?) E-rated tires on all their conversions. I think D-rated tires are at the edge of safety for a fully converted van.

I found my van handled better with the E-rated tires too.

Herb

In 2003 I put E rated tires on my F-250 and noticed handling difference instantly. So when I ordered my SMB in 2009 I made sure it would have E rated tires on it. I agree with you Herb that SMB should mandate E rated tires.

Woody

**daveb** · 10-19-2010, 08:57 PM

American tire company told me they had a memo sent to them about D's on a sportsmobile and told me they couldn't put them on even if I wanted them. Mine are 285/75-16 BFG-AT's and the tires are melting away faster than the D's I had on before.

I really want a mud terrain in the 305 version E-rated but don't know if they will rub in a hard turn in a gully. I don't want to rip off my bushwackers. The other problem is my SMB trailer that uses the same tire. The way I understand it is the 305's and 285's are the same height so if I got into a jam I could use one of the 285's as a spare on the van W/O messing something up...Correct?

Dave

Roonie · 10-19-2010, 09:19 PM

Quote:

Originally Posted by daveb

I really want a mud terrain in the 305 version E-rated but don't know if they will rub in a hard turn in a gully. I don't want to rip off my bushwackers. The other problem is my SMB trailer that uses the same tire. The way I understand it is the 305's and 285's are the same height so if I got into a jam I could use one of the 285's as a spare on the van W/O messing something up...Correct?

Dave

My understanding is that is is fine to use the 285 as a spare since they are the same height. I know some 4x4 guys prefer the 285 spare when they are running 305's because it saves room on the back of their vehicle and is lighter for the tire carrier.