Hard Tires vs Soft Tires

[DaveBunker]

Gentlemen, I own a 2014 Fleetwood RV. I bought it new and it came with Goodyear G670 245 / 70R / 19.5. The coach now has 11.000 miles on it. I'm leaving on a long road trip in July and want a better ride.

I visit with fellow RVers at various parks and leave thinking my tires are like Fred Flintstone tires. Hard as a rock and not very good taking road bumps.

Overall everyone tells me to put Toyos on the front and you will see a huge difference. Wait and do the same with the rear 4. Is this true?

I priced two at Less Schawb for $800.

I welcome all opinions and appreciate any help.

Dave Bunker

[bobcovey]

Dave,

I am not a fan of the G670's, but changing tire brands is not going to fix your problem. Weigh your coach with full fuel and water tanks, and all the gear, people and dogs that you usually travel with. You want individual wheel weights but axle weights are a good starting point. Then look at the Goodyear inflation tables for you tires and set air pressure accordingly. CAT scales at many truck stops are a good starting point.

Cheers,

[Steve Ownby]

Originally Posted by DaveBunker

Gentlemen, I own a 2014 Fleetwood RV. I bought it new and it came with Goodyear G670 245 / 70R / 19.5. The coach now has 11.000 miles on it. I'm leaving on a long road trip in July and want a better ride.



I visit with fellow RVers at various parks and leave thinking my tires are like Fred Flintstone tires. Hard as a rock and not very good taking road bumps.



Overall everyone tells me to put Toyos on the front and you will see a huge difference. Wait and do the same with the rear 4. Is this true?



I priced two at Less Schawb for $800.



I welcome all opinions and appreciate any help.



Dave Bunker

I think new tires would be a disappointment. Ride quality is largely "baked in the cake" when the coach was built. The best thing you can do is weigh you coach and inflate you tires according to the Goodyear chart.

[TBS-POPS]

Just from my experience 19.5's just don't ride well over all and goodyear g670' s are garbage. Toyos may ride a bit better but yes check your tire pressures.

[jelag]

I wore out a set of Bridgestones on my rig, did some front end work to bring that back to 100% and remounted Toyo from Schawb... I'm very unhappy... have some vibration and what I believe is an out of round tire with some very odd tire wear... Schawb tells me that the tires will go the same mileage as my old Bridgestones... but they have a funny wear pattern I didn't see on the Bridgestones... I asked for them to put a tire run out gauge on the tires... and they said it was a waste of time... they did offer to re-balance for $12 each.. something I thought was included in the new tire purchase for life.... BTW those went 90K miles... very happy... So now a call to Toyo... their truck tire customer service line.. I'm told that they rely on Schawb and if they say its OK its OK.... but if I want to pay for new tires and send the old ones back to them... and if they are defective... they would pay... I'm now 20K miles into this...

I went out.. bought a new set of Bridgestone's and threw the Toyo's away.. and guess what... my vibration is gone...

[Ron_H]

Any tire will ride hard if it is overinflated. Are you sure your's are correctly inflated?

The PSI number on the tire sidewall is the "Maximum" pressure for the tire to carry its maximum weight. Since a dealer does not know what your coach will weigh after its loaded they tend to automatically inflate all tire for their maximum load capacity. This practice is guaranteed result in many tires being overinflated and rough riding.

The only way to set your tire pressures correctly, and hence enjoy the best ride and get the best performance from your tires, is to get the 4-corner weights for your (loaded) RV, compare those weights to the tire manufacturer's chart and inflate or deflate your tires to those pressures.

Our coach's tire are marked for 123 psi for maximum weight carrying capacity and that is what they were set to when we picked the coach up from the dealer. After loading the coach up and reading to an RV rally we had the 4-corner weights taken and looked them up on the Michelin tire guide. The correct pressures for our actual weight was 110 psi on our front axle tires and 95 on our drive and tag axles. Those pressure adjustments made a huge difference in how the coach road and handled - a huge improvement.

[Ray,IN]

Originally Posted by bobcovey

Dave,

I am not a fan of the G670's, but changing tire brands is not going to fix your problem. Weigh your coach with full fuel and water tanks, and all the gear, people and dogs that you usually travel with. You want individual wheel weights but axle weights are a good starting point. Then look at the Goodyear inflation tables for you tires and set air pressure accordingly. CAT scales at many truck stops are a good starting point.

Cheers,

That, IMO is a good way to ruin your tires. All load/inflation charts show the absolute minimum air pressure to support the corresponding load.
Goodyear and Michelin both say to never inflate to less than the mfgrs. tire placard air pressure. Yes, they both have charts, both showing the minimum air pressure, not the optimum. You'll find many threads here with links to prove what I just said.

[jrusselltx]

Sorry, but for RV (truck) tires, the pressure on the sidewall is the MINIMUM pressure to carry that weight, not the maximum that the tire can be inflated to. Car tires are marked with the maximum allowed pressure. But the advice is still valid. Weight first, and then check the tire charts which also show the MINIMUM pressure to carry that weight. I usually add 5 to 10 pounds to that pressure to allow for pressure gauge issues and for some safety factor.

[RandyKathyM]

Originally Posted by jrusselltx

Sorry, but for RV (truck) tires, the pressure on the sidewall is the MINIMUM pressure to carry that weight, not the maximum that the tire can be inflated to. Car tires are marked with the maximum allowed pressure. But the advice is still valid. Weight first, and then check the tire charts which also show the MINIMUM pressure to carry that weight. I usually add 5 to 10 pounds to that pressure to allow for pressure gauge issues and for some safety factor.

My tire say Maximum Pressure at Max load.

[bobcovey]

Originally Posted by Ray,IN

That, IMO is a good way to ruin your tires. All load/inflation charts show the absolute minimum air pressure to support the corresponding load.
Goodyear and Michelin both say to never inflate to less than the mfgrs. tire placard air pressure. Yes, they both have charts, both showing the minimum air pressure, not the optimum. You'll find many threads here with links to prove what I just said.

You caught my attention with that statement because I thought that I had done my homework on tires and inflation. So, I went back to Goodyear, specifically: https://www.goodyeartrucktires.com/p...dinflation.pdf
Nowhere in this document do I see what you claim. Quite the opposite; Goodyear provides a calculation chart to help determine precise pressures for load and speeds.
The placard air pressures in my coach are for GVWR, not actual weights, and only valid for the OEM tires, coincidentally Goodyear G670s. They are not accurate for actual weights and other brands of tires.
I will stand by what I recommended to Dave: weigh the coach and adjust per the charts. 4 corner weighing is certainly preferable, but axle weights are better than guessing. I did forget to add that like Jim I also add 5 psi.
I recently replaced the G670s with Toyo M144A tires. The Toyos do ride and handle better than the Goodyears, but those differences would not have justified the cost, at least to me. I needed new tires and picked the Toyos based on cost, reputation and availability when I decided to write the check.

Cheers,

[Steve Ownby]

Originally Posted by bobcovey

You caught my attention with that statement because I thought that I had done my homework on tires and inflation. So, I went back to Goodyear, specifically: https://www.goodyeartrucktires.com/p...dinflation.pdf

Nowhere in this document do I see what you claim. Quite the opposite; Goodyear provides a calculation chart to help determine precise pressures for load and speeds.

The placard air pressures in my coach are for GVWR, not actual weights, and only valid for the OEM tires, coincidentally Goodyear G670s. They are not accurate for actual weights and other brands of tires.

I will stand by what I recommended to Dave: weigh the coach and adjust per the charts. 4 corner weighing is certainly preferable, but axle weights are better than guessing. I did forget to add that like Jim I also add 5 psi.

I recently replaced the G670s with Toyo M144A tires. The Toyos do ride and handle better than the Goodyears, but those differences would not have justified the cost, at least to me. I needed new tires and picked the Toyos based on cost, reputation and availability when I decided to write the check.



Cheers,

I agree with you Bob. The placard is for OEM tires and the GVWR of the coach. I agree that if you haven't been weighed than that is the inflation to run until you do get weighed. I also agree that all truck tire inflations are the minimum psi for the weight. I always add a minimum of 5 psi to that.

It's easy the get "wrapped around the axle" over inflation pressure. Pressures will fluctuate with ambient temp and at travel speed. If my cold inflation (morning) pressure is up 5-10 psi because of temp, I don't adjust down. My aim is to establish a psi range for traveling with the caveat that the pressure never be below that pressure on the chart plus 5 psi.

[Gary RVRoamer]

My tire say Maximum Pressure at Max load.

Not if it's a G670. Or a Toyo or a Continental either. Their standard wording is "Max xxxx lbs at zzz psi". The wording is pretty much standardized by the tire manufacturer's association and conforms to federal requirements for tire labeling. It is the pressure (psi) required to support the stated maximum load. It is not the max psi the tire can handle, and several manufacturers give guidance on when over-inflation is useful.

However, if you are reading from the sidewall of a passenger car tire, the wording and meaning is slightly different. See Jim Russel's message (above) on this subject.

[ChasA]

Dave Bunker,
My previous motorhome had the same Goodyear tires and they rode hard too. I replaced them with Sumitomos of the same size and load rating inflated to the same pressure. The Sumitomos rode much softer. I can't remember the tire model but they were ST(???). They cost me around $2300 for 6 mounted and balanced.

[FreedomDream]

As others have said here, weigh your coach loaded for travel with all the people who will be traveling with full fuel tank, the water level you will travel with. Inflate tires to level prescribed by your tire manufacturer at this weight. This will give you the best ride quality. This is is what the tire engineers have designed the tire for. They would not publish information that would in any way be detrimental to their product. Go with what the engineers say and not opinions of people who don't really know.