Tire Recommendations

[Fmca-fleetwood]

2005 Fleetwood Excursion with Cat C7 turbo

Should I replace 11 year old Goodyear tires even though only 40k miles, they've been covered and stored with coach on levelers but not off the ground. Great tread, no cracks but dot code is 3704.

Everything I read and word from others is replace no later than ten years old regardless of visual inspection results.

What do you think about replacing front tires this year and replace rears in future years? I'm thinking of biting the bullet and replace them Amal at once. I plan to put 11k miles on the tires in 2016.

If I do replace them what do you think about going with a larger diameter tire for better mileage at a lower sustained engine rpm? Current tires are Goodyear G670 RV, 275/70R22.5, load range H. Tread 5 plies steel cord, sidewall 1 ply steel cord. Its been suggested to go with a 305 tire. I have a Cat C7 turbo. At 60-65 mph I'm running at ~2100 rpm getting 7.5 to 8.5mpg. Mpg should improve if I can do 60-65mph @1800 rpm. What gotchas should I consider?

Any recommendations for tires to consider? A relative owns a large number of semi tractors and trailers. He recommends Michllan, he is not a fan of Goodyear tires.

I will appreciate any input on any or all my questions. This is my first year with this beast and looking forward to having a great time.

[wolfe10]

Welcome to the FMCA Forum.

Can't imagine anyone suggesting hitting the road with 11 year old tires.

Be sure to check out the FMCA Michelin Fleet Pricing Program.

[hermanmullins]

FMCA-Fleetwood,

As Brett said, not a good idea. Although your tires may look good on the outside take a look between the treads. On 11 year old tires I can guarantee you will find cracking. When talking tires the ole saying "better safe than sorry" is right on.

Herman

[blakeloke]

Welcome to the forum....you'll see that the are many experts that can help. Me not included in that. We had Goodyear 670's on our coach and replaced then with Michelins at the 5 year mark. I could not believe the difference in ride and handling.

I'm with Brett and Herman.....don't chance running on older tires. Even if they look good from the outside.

Blake

[kaypsmith]

From 275 to 305 is a pretty substantial increase in tire width, about 1.25 inches. You didn't say what height but 75 to 75 will about 1.5 inches to diameter, nearly 4.75 circumference.

That is a lot of added size, the motor should be able to handle that, but clearances would be my main concern in changing that drastically. take into consideration width alone could cause tire kissing on the duals, not a good idea at all, could cause premature tire failure.

I do agree that replacing 11 year old is to your best interest. Hopefully tireman9 will read your post. His advice on this topic will be interesting and very informative.

Also a call to Fleetwood to check their maximum recommend for your unit will be in your best interest.

Happy Holidays and motoring,

Kay

[roadster27]

2005 Fleetwood Excursion with Cat C7 turbo

Should I replace 11 year old Goodyear tires even though only 40k miles, they've been covered and stored with coach on levelers but not off the ground. Great tread, no cracks but dot code is 3704.

Everything I read and word from others is replace no later than ten years old regardless of visual inspection results.

What do you think about replacing front tires this year and replace rears in future years? I'm thinking of biting the bullet and replace them Amal at once. I plan to put 11k miles on the tires in 2016.

If I do replace them what do you think about going with a larger diameter tire for better mileage at a lower sustained engine rpm? Current tires are Goodyear G670 RV, 275/70R22.5, load range H. Tread 5 plies steel cord, sidewall 1 ply steel cord. Its been suggested to go with a 305 tire. I have a Cat C7 turbo. At 60-65 mph I'm running at ~2100 rpm getting 7.5 to 8.5mpg. Mpg should improve if I can do 60-65mph @1800 rpm. What gotchas should I consider?

Any recommendations for tires to consider? A relative owns a large number of semi tractors and trailers. He recommends Michllan, he is not a fan of Goodyear tires.

I will appreciate any input on any or all my questions. This is my first year with this beast and looking forward to having a great time.

My first guess is the tires are cracked between the treads and backside of tire, the part that never gets cleaned and considering 40k mileage on them have paid for themselves. A wider tire will not help fuel mileage as there is more tread on the ground and more friction, but a taller tire would help as it would bring rpm down, 2100 seems quite high , 60 mph on my 275 x 75 x 22.5 are 1650 which are 5 years old Toyo tires that I will replace in 2 years before we go on our full time trip and I would go with 80`s or 85`s next tire change to reduce RPM , I have been researching Bridgestone tires but the Toyos`s have been good , and substantially cheaper than Michelin.

Please change all of them and sell the old ones to your trucker family to run off the tread on their trailers to help recoup a little.

[Fmca-fleetwood]

Thanks to erroneous that contributed to my questions. All the input was valuable and drove additional esearch by me on the topic.

I am going to replace all 6 tires and go with a taller tire. Before I select the tire size I plan to send Fleetwood for confirmation that the tire size selected is acceptable for my coach.

Merry Christmas

[wolfe10]

Here is the spec sheet on your chassis: http://www.fcccrv.com/wp-content/uploads/oem_pdfs/Fleetwood/XC0106-2005.pdf

The OE size/load range tire should be fine assuming you are within your GAWR (Gross Axle Weight Ratings).

And, before going to a taller tire, please make sure that your tach and speedometer are accurate. 2100 RPM in 6th gear should give you 74 MPH.

Formula: (RPM X 60) divided by (rear axle ratio X tire revolutions per mile X transmission ratio)= MPH

(2100 RPM x 60) / (4.78 rear axle ratio x 548 tire revolutions per mile x .65 transmission ratio in 6th gear) = 74 MPH

[wildebill308]

I think Brett has a good point.

Bill

[Fmca-fleetwood]

Thanks Brett, I suspect my speedometer and Tach are right but my memory is flawed (as is my spelling). Thanks for the formulas. I will double check everything before I choose the tires.

Thanks for the link to the chassis specs. I need to check the manuals that the previous owner provided with the coach. Everything provided says I have a Spartan Chassis.

I will double check the gear ratios and other parameters to calculate what my RPM is at 60 and 65mph. Hopefully, Fleetwood or Spartan can use my VIN number to confirm what I have and tell me what tire sizes (width, height etc...) are good for my rig. I'd prefer not to mess around or get cute when it comes to something as important as the tires.

This forum has been very helpful. I suspect I will be back often as I use my coach come this summer.

Time to actually retire and enjoy some traveling.

[wolfe10]

Yes, if a Spartan chassis, contact them with your VIN to verify rear axle OR crawl under and look at the tag on the axle itself.

And, the GVWR plaque (usually near the driver's area) will have the OE tire size.

[hermanmullins]

Fleetwood,

I know my speedometer is off (slow). Therefore I drive by the speed shown on my GPS. On both our SUV and my truck their speedometers are dead on, however the coach is 3 miles slow at 65. So I set my cruise by the GPS. I can use the trip mode to get a pretty accurate MPG reading.

Herman

[wildebill308]

Yes I found my speedometer to be 5.8% slow. I to use my GPS speed. I always felt it was slow because I would creep up on traffic on the freeway. You know the ones who wouldn't go over if there was a forest fire catching up to them. At indicated 65 I was doing 68+.

Bill

[wayne77590]

Below is a link that may be helpful to everyone for future purchases. I recently went from Michelin to Toyo and the link was a great help:

Tire Size Calculator

[desertdeals69]

Yes I found my speedometer to be 5.8% slow. I to use my GPS speed. I always felt it was slow because I would creep up on traffic on the freeway. You know the ones who wouldn't go over if there was a forest fire catching up to them. At indicated 65 I was doing 68+.

Bill

Your error is easily corrected, you have to know the revs per mile and the rear end gear ratio and find someone with the laptop that has the right program. Every time I have changed my ratio, 4 times, I had my friend recalibrate my speedo. It takes about 5 minutes.

[2mahams]

After driving home this afternoon on 6 new Michelin XZA2 Energy 275/70R22.5, don't think there is a better tire. What a smooth & quiet ride after replacing the 10yr old goodyear G670Rv tires @ 120psi. The new tires are J load and it was recommended to run 105 -110psi. They also found the LF wheel seal leaking and fixed that with a new seal & a set of brake shoes since they were soaked with oil. If in the Winston- Salem, NC area see Ted at Snider tire, the FMCA program was easy and they have done many.