2015 Ellipse tire pressure 42QD

KatieVL · 07-13-2018, 07:01 PM

I have not had a chance to weigh my new to me Ellipse. Wondering what those of you that drive one have your steer and rear tire pressures at. Please give me a ballpark to set them

BobC · 07-13-2018, 07:25 PM

Fill them according to the information on the plate attached to your vehicle until you have accurate four-corner weights. Anyone else's PSIs are meaningless since you have no idea how your weights compare to theirs and using their PSI info could be dangerous. you'd also be assuming they know what they're doing. Here's a link to an IRV2 discussion on this topic:

Tire Inflation Tables Work - iRV2 Forums

Here's a link to the best online site I've found (created by a retired tire engineer): RV Tire Safety: Another post on Cold Inflation Pressure and "Ambient" temperature.

bobmac · 07-13-2018, 08:08 PM

Once you have loaded the coach, best to head to a truck stop with CAT scales. You need to know your weights . Download the Michelin RV tire brochure for details on the different tire types or the maunfacturer of your tires. Good luck.

Lv2Roam2 · 07-14-2018, 06:27 PM

We weigh our coach every two years at the Freightliner Factory Center in Gaffney, SC, which we highly recommend for chassis/engine service work.

Our coach is loaded for full-time use at just under 40,000 lbs. Our steer 295 / 80 / 22.5s are inflated to 120 lbs cold. Our drive / tag 275 / 80 / 22.5s are inflated to 90 lbs cold.

As stated - load your coach, empty the grey / black tanks, fill the fuel / fresh water tanks - and get a 4-corner weight. That's the best way to determine tire pressures, and rebalance air bags and weight distribution if needed.

Meridian42e · 07-15-2018, 08:42 AM

I weighed my loaded Meridian 42E with a similar tag chassis to the 42QD Ellipse, and I was pleasantly surprised how underloaded the rear axles were. Unfortunately there wasn't much room left on the front axle, so it stays at maximum pressure, but I'm going to drop the rears down to 90.

BobC · 07-15-2018, 09:17 AM

Quote:

Originally Posted by Meridian42e

I weighed my loaded Meridian 42E with a similar tag chassis to the 42QD Ellipse, and I was pleasantly surprised how underloaded the rear axles were. Unfortunately there wasn't much room left on the front axle, so it stays at maximum pressure, but I'm going to drop the rears down to 90.

I'm curious, do you think the differential is just due to the coach itself or the way you've loaded it? Were your fuel and freshwater tanks full? Maybe with the rear Diesel engine, it's just overbuilt in the rear.

Meridian42e · 07-15-2018, 11:07 AM

Quote:

Originally Posted by BobC

I'm curious, do you think the differential is just due to the coach itself or the way you've loaded it? Were your fuel and freshwater tanks full? Maybe with the rear Diesel engine, it's just overbuilt in the rear.

It was fully loaded including water, fuel, and even us

(that new CAT scale app lets you activate, pay and weigh from the cab).

I personally think the 42E design pushed past the standard 20,000 lb rear axle and required the 10,000 lb tag, but not by much. As a result, we gained most of the capacity of that extra 10,000 lbs that was unused and it pushed up our GVWR. Fully loaded I'm at 36,640 and our GVWR 44,000 lbs.

As far as loading, I'm just not sure what I could push to the back. The rear engine, plus the tag, take out most of the storage back by the axle. The water tanks are near the rear axle already, and so is the kitchen. Forward is the generator and our cargo which honestly is lawn chairs, screen tent, and some comfort stuff, nothing real heavy. Our 42E has a motorcycle lift (cruiserlift) mod on the back, and I imagine it is an ideal platform for carrying a bike on the back.

BobC · 07-15-2018, 11:56 AM

Nice to know you have the extra capacity since the GVWR also takes into account the braking capacity, etc. It would give me peace of mind, safety-wise.

Meridian42e · 07-15-2018, 01:13 PM

I'm going to reweigh at another CAT before I drop the pressure, just to make sure it's reasonably accurate.

jerichorick · 07-17-2018, 09:34 AM

Quote:

Originally Posted by KatieVL

I have not had a chance to weigh my new to me Ellipse. Wondering what those of you that drive one have your steer and rear tire pressures at. Please give me a ballpark to set them

One problem I have read is that the tag is not always adjusted correctly. I recommend that you take a trip to the Freightliner factory service center in Gaffney, SC. Make an appointment first. Have them go through your chassis, weigh the coach and recommend tire settings. At this time I agree with the others. Use the values on the tag next to the drivers seat.

I have had TST & EEZ TPMS. I like the EEZ over TST. You may have an onboard TPMS already. Very valuable tool. Make certain it is calibrated to your tire requirements.

Brutusiii · 07-19-2018, 06:36 PM

Quote:

Originally Posted by jerichorick

One problem I have read is that the tag is not always adjusted correctly. I recommend that you take a trip to the Freightliner factory service center in Gaffney, SC. Make an appointment first. Have them go through your chassis, weigh the coach and recommend tire settings. At this time I agree with the others. Use the values on the tag next to the drivers seat.

I have had TST & EEZ TPMS. I like the EEZ over TST. You may have an onboard TPMS already. Very valuable tool. Make certain it is calibrated to your tire requirements.

While you are at gaffney getting your coach weighed and serviced, take the Freightliner class. Mike Cody does an excellent job of training on this topic and several others. Very worth the time.

Rbuxton · 07-21-2018, 04:47 PM

I keep my 2013 Tour 42 QD at 120 lbs, all positions and has served me well. 120 Lbs is the recommended maximum pressure.

mwgettler · 07-21-2018, 06:45 PM

I’ve got a 14 42’ QD with tag axle. I’d start with max tire rating - remember it is a cold tire rating. My tires are rated 120 psi. After I weighed the coach by axle my total weight is 37k lbs. I run front at 110psi and rear at 90. Both of those number are a little above the calculated pressure.

Tireman9 · 07-21-2018, 07:51 PM

Post to all. While using axle weights from a truck scale is closer that the vehicle tire placard. Until you get actual "4 corners " weights I suggest people use truck scale axle weights but assume one end is loaded to 53%, do the math and then using the tables use the 53% number to learn the minimum inflation.

RE what tables to use. If you have Michelin you should use the Michelin tables. Any other brand it is ok to use the tables from any other brand. Michelin has a few sizes that were designed using European standards 9and metric system) then when they transferred the tire to the US they had to do some unit conversions and some rounding of the results. This results in a few sizes being slightly different than the rest of the tire companies in the US. (Bridgestone, Goodyear, General, Toyo, Firestone, Continental, and Hankook all seem to use identical tables)

Meridian42e · 07-30-2018, 12:13 PM

Just went to Forest City from Denver and back with 90 psi in my rear axles - nice ride!

I know it's not a real scientific comparison

, but I don't think I'll go back to 120 psi.

Tireman9 · 08-02-2018, 09:21 PM

Quote:

Originally Posted by Meridian42e

Just went to Forest City from Denver and back with 90 psi in my rear axles - nice ride!

I know it's not a real scientific comparison

, but I don't think I'll go back to 120 psi.

Just remember that for the tires it is the actual load on each tire position and not the GVWR that you need to consider.

Did I read yournumbers correctly? you have 23,480 on a 20,000 axle?

20# on the tag? 13,140 on the front. Somethnig isn't right. Ideally you should not load the tires to more than 85% of their max or if you know the actual load on each end of each axle you would use that number to look up the MINIMUM onflationfor all the tires on that axle and ass 10% to the minimum infl for your Cold set pressure.

Meridian42e · 08-03-2018, 10:25 AM

Quote:

Originally Posted by Tireman9

Just remember that for the tires it is the actual load on each tire position and not the GVWR that you need to consider.

Did I read yournumbers correctly? you have 23,480 on a 20,000 axle?

20# on the tag? 13,140 on the front. Somethnig isn't right. Ideally you should not load the tires to more than 85% of their max or if you know the actual load on each end of each axle you would use that number to look up the MINIMUM onflationfor all the tires on that axle and ass 10% to the minimum infl for your Cold set pressure.

No-no, it was 23,480 lb. on both the drive and tag. The 20 lb on the scale behind my axles must have just been an anomaly, as I didn't have anything on that scale. Sometime again when I'm fully loaded I'll reweigh it with the drive and tag on different scales.

Nobody was at the rally to weigh the individual wheels, so I guess if I come across it sometime I'll do it for additional information.