wtbuck12 Report post Posted November 16, 2020 Looking for opinions. Left south Louisiana with temperature in the 80's arrived in North Carolina with temperatures in the 30's. Needless to say, tire pressures in the morning are considerably lower, should I adjust back to 95/90 psi or run as is? Share this post Link to post Share on other sites
rossboyer Report post Posted November 16, 2020 Adjust pressure before driving at coldest temperature. IE: I use 107# for all tires. Do not decrease pressure through the day. Adjust again the next morning, cold. Share this post Link to post Share on other sites
richard5933 Report post Posted November 17, 2020 2 hours ago, rayin said: OTOH, you could do as I, inflate to the Federal Tire Placard listed pressures in the vehicle and never half to adjust tire pressure because of ambient temperature. How does that work? Whatever you choose as the pressure you want in the tires, you'll need to adjust as the weather gets cold. If you set to the placard pressure in August you'll have to readjust the pressure as fall and winter come on, unless you're staying where the weather never changes. Share this post Link to post Share on other sites
rossboyer Report post Posted November 17, 2020 The placard is not necessarily the proper pressure based on actual weight. Weigh, check charts for your tires, inflate while cold to the pressure you found on the chart. Two manufacturers have told me to add ten pounds for safety. Share this post Link to post Share on other sites
manholt Report post Posted November 17, 2020 I agree with Richard and it can be a catch 22 question. If I have in the 30's temps and we're going to our other house in South Texas, I don't adjust my PSI, it's 20-30 degrees warmer where we go and it's a 5 hour trip. If we go the 250 miles north to Dallas, then I will add air! The caveat is how big & how much does your coach weigh for travel to begin with? Mine is over 64,000#...way more than Ross or Ray! Tires are also bigger, 365 front and the other 6 are 315's! Full fuel is 200 gallons...that's variable weight, but fresh water at 140 gallons is not. Share this post Link to post Share on other sites
manholt Report post Posted November 17, 2020 RayIN, you got a point, but a rougher ride! Share this post Link to post Share on other sites
rossboyer Report post Posted November 17, 2020 2 hours ago, rayin said: Look at the placard in your bus. The listed air pressure is adequate for temperature changes. Does anyone assume commercial bus drivers adjust tire air pressure as they drive from CA to WY in December? For RossBoyer; The NHTSA (another link) says to inflate to the Federal Tire Placard in the vehicle, that's what i do for all my vehicles. What do you do for your autos when you are the only occupant vs having 4 passengers, do you adjust tire pressure to the load ? If I did the Federal recommendation, I would be grossly under inflated for the actual weight when I had all 4 corners weighed. In 25 years the only tire problem I have had was a bad valve stem. You do what you want, but I would rather be safe. Share this post Link to post Share on other sites
richard5933 Report post Posted November 17, 2020 9 hours ago, rayin said: ...I wonder if anyone runs lower pressure in their auto tires simply to obtain a smoother ride? Yes Within the margin allowed by the tire manufacturer, but many luxury cars have achieved their soft ride by running the pressure at the lower end of the acceptable pressure range. Those manufacturers interested in fuel economy tend to inflate towards the upper end of the range, comfort the lower. With modern suspension systems this is not as common, but it's been a practice of manufacturers for a long time. Share this post Link to post Share on other sites
wtbuck12 Report post Posted November 17, 2020 Thanks for the opinions. Sounds like I'll be adding air before heading home. Share this post Link to post Share on other sites
wildebill308 Report post Posted November 17, 2020 12 hours ago, rayin said: I wonder if anyone runs lower pressure in their auto tires simply to obtain a smoother ride? Well actually that was a big part of the problem with the Ford Explorer from 1996-2000. https://en.wikipedia.org/wiki/Firestone_and_Ford_tire_controversy That and a lot of pore design. Bill Share this post Link to post Share on other sites
richard5933 Report post Posted November 17, 2020 Yes - there was a problem with the tires on the Ford Explorer from those years. Not the only tire problem that's happened over the years. However, the exception doesn't make the rule. Auto manufacturers have used tire pressures to balance comfort and economy since the early years of the auto industry. The problem with tires on the Explorer aside, the answer to the question is still 'yes', lower tire pressures are used for a smoother ride in cars. Rarely will the recommended tire pressure for a car be the sidewall max. Share this post Link to post Share on other sites
manholt Report post Posted November 17, 2020 For about 18 years, I ran my coach tires at sidewall PSI, weight of coach for travel? Who knew? Weight and Temp was not part of the equation, since we all ran non steel belted, Radial tires! TPM did not exist, so at every fuel stop/rest area, we would "Thump" the inner drive tires! I still do that once a day! I ran Kelly's back then! Share this post Link to post Share on other sites
rossboyer Report post Posted November 17, 2020 Maybe the Tireman will explain. I gave tried. You do what you want. I will do what is recommended for my corner weighs and tire chart from the manufacturer of my tires. Enough said. Share this post Link to post Share on other sites
manholt Report post Posted November 18, 2020 (edited) Ross, Tireman has on numerous posts! Since the invention of TPS and coaches running Radial Steel Belted tires, we know what caused all the blow outs on older models. In Texas, during summer, you do not want to run at max cold. My chart say's 115 psi front cold and 100 on rear drive and tag, cold. I use a 7% +/- during winter and no +, only - in Summer! Edited November 18, 2020 by manholt Share this post Link to post Share on other sites
richard5933 Report post Posted November 18, 2020 On 11/16/2020 at 8:53 PM, rayin said: IMO that is the whole point of operating ties with lower pressure per tire load/inflation charts,to simply attempt to obtain a smoother ride. BTW Goodyear says that is futile even though they provide load/inflation charts to prevent under-inflation. I wonder if anyone runs lower pressure in their auto tires simply to obtain a smoother ride? Curious why you think that there is no downside to running at a higher pressure than necessary? It's not just a smoother ride - there is a negative effect on handling and braking when running higher-than-necessary air pressure. Also, the information on the Federal placard is static and often just represents one possible setup available on the chassis. If I were to follow the information on my Federal placard I'd still be running bias-belted tires and an air pressure way out of line with what I run in the current tires. The Federal placard on my coach presents the max load with the standard OEM tires. The operator's manual on my coach has about 4 pages of load & inflation tables which give detailed information for the available tire and wheel options. This has long been a more complex calculation than just looking at the Federal placard. Share this post Link to post Share on other sites
manholt Report post Posted November 18, 2020 RayIN. Yes, I run a lower tire pressure when I'm off roading in the desert and mountains. My Jeep tires hold 40 psi max cold, I run in the 12 psi to 20 psi depending on terrain! When I get to pavement, I air up to 35 hot. Share this post Link to post Share on other sites
richard5933 Report post Posted November 18, 2020 1 hour ago, rayin said: ... I asked about carrying 4 passengers in a car compared to only the driver. That weight difference is substantial yet no-one I know adjusts car tire pressure for the corresponding load. ... Funny - I can remember my father trying to do the math when we loaded up the family's station wagon for our annual trip to the Catskills from NJ. He tried his best using a bathroom scale to adjust the tire pressure according to the sticker on the doorpost based on how much we were carrying. Maybe that's where I get it from. Of course, that station wagon had Firestone 500s on it so we were doomed to have problems regardless. And we did. Rear blowout on an elevated section of Rt. 22 heading into NYC. Yours truly was the designated tire monkey, even though it took standing with all my body weight on the jack handle/lug wrench to break them free when I was a kid. Ah, the good ole days. Share this post Link to post Share on other sites
hermanmullins Report post Posted November 18, 2020 Firestone 500's and tire problems, enough said. Herman Share this post Link to post Share on other sites
wildebill308 Report post Posted November 18, 2020 7 hours ago, manholt said: RayIN. Yes, I run a lower tire pressure when I'm off roading in the desert and mountains. My Jeep tires hold 40 psi max cold, I run in the 12 psi to 20 psi depending on terrain! When I get to pavement, I air up to 35 hot. Made me remember someone on a different forum who was complaining that his tires on his new tires on a class A were blowing out. Found out he was lowering the air pressure the same way to run it on the beach. We need to ask "Tire Man" if that could cause a problem. Bill Share this post Link to post Share on other sites
kaypsmith Report post Posted November 18, 2020 I'm sure glad that I have air ride, smooth ride even with tires inflated to max. Or is there something wrong with my coach? LOL💤 Share this post Link to post Share on other sites
wildebill308 Report post Posted November 19, 2020 I don't care if you have oversized balloon tires 75 from McKinney to Durant will shake the dishes. Bill Share this post Link to post Share on other sites
jleamont Report post Posted November 19, 2020 11 hours ago, kaypsmith said: I'm sure glad that I have air ride, smooth ride even with tires inflated to max. Or is there something wrong with my coach? LOL💤 Ditto! The only thing I notice is it slightly wanders if they are overinflated (i.e. set to MAX PSI). I top off my pressures to the MAX on the side wall when I park it for the year. One year I didn't think about it and took it on road test after doing some work in early spring. Couple the high pressures with the coach being completely empty and it felt a little squirrely but it didn't ride harsh. Share this post Link to post Share on other sites
manholt Report post Posted November 19, 2020 Bill, letting out half or more air in tires, only work if you have bead locks! I've been up 75 and had no problems in my AC Tradition after I got new shocks! I have the same harsh ride on the King Aire, new shocks are on the wish list, but backordered...like everything else! Same with my Fox 2.0 shocks for Jeep & hard top! 4-6 weeks! 🤬 Share this post Link to post Share on other sites
wildebill308 Report post Posted November 19, 2020 8 hours ago, manholt said: Bill, letting out half or more air in tires, only work if you have bead locks! Hay, didn't see it but it had to be true it was on the internet. What shocks are you looking at? I am thinking Koni FSD on the back and Koni EVO on the front. Share this post Link to post Share on other sites
