Tow Vehicle Tire Inflation for towing

[John in Santa Cruz]

Originally Posted by Raspy

It seems so many new cars have a more "performance" type suspension design, than comfort oriented. Of course Mercedes is famous for comfort while still handling correctly. My '83 300 SD is that way. Soft, but well mannered and under control in corners. Do you think some of the harshness you mention comes from the lower profile tires so many are using now?

yes, yes, and yes.

putting /55R19 wheels on a SUV is ridiculous, tires that size belong on a racetrack. I blame MTV and all the glamorization of ghetto low riders for this trend.

my 300E and my wife's 300TE have 195/65R15 tires, which suit both cars very nicely. my truck has 265/75R16, which also suit it very nicely.

btw, I believe your W126 series 300SD had the old school swing-arm IRS... my W124 series E classes pioneered modern 5-way multilink rear suspension, which makes an amazing difference in ride and control, especially on high G cornering... The S class got this with the W140 series in 1992 or so. With multilink, the rear wheels stay parallel regardless of the suspension travel, so you don't get into negative camber on hard turns when the body is leaning.

[Jon in AZ]

Our 2000 Sienna had 15” wheels. Our 2006 CR-V has 16”, our 2011 Pilot has 17”, and our recent addition, a 2018 RAV4, has 18”.

Am I seeing a pattern here?

[AC0GV]

Originally Posted by Jon in AZ

Our 2000 Sienna had 15” wheels. Our 2006 CR-V has 16”, our 2011 Pilot has 17”, and our recent addition, a 2018 RAV4, has 18”.

Am I seeing a pattern here?

Yes, less and less tire for more and more $$$

[Wayne Collins]

Originally Posted by Jon in AZ

Our 2000 Sienna had 15” wheels. Our 2006 CR-V has 16”, our 2011 Pilot has 17”, and our recent addition, a 2018 RAV4, has 18”.

Am I seeing a pattern here?

Those are the rim diameters, what about the tire aspect ratios?
They could all have the same overall diameters and rolling radii.

[ZachO]

They often do, I think that's the "problem" we're seeing here. Same overall size, but less tire, more rim, meaning less rubber and air and whatever purpose all that air and rubber serve in handling.

[Jon in AZ]

The Sienna was 70 series, the CRV and Pilot are 65 series, and I think the RAV4 is 60 (55?) series. The general trend has been toward bigger rims with lower profile tires. Good for handling, bad for ride quality and off-highway use.

[Civilguy]

Our JGC was normally equipped with
20-Inch x 8.0-Inch Tech Gray Aluminum Wheels
265/50R20 BSW All Season LRR Tires

The "Off-Road Adventure II" package substituted
18-Inch x 8-Inch Satin Silver Aluminum Wheels
265/60R18 BSW All Season All Terrain Tires

60-series tires on satin-silver aluminum wheels for "off-road" adventure?!?

Coming from the era of stock bulbous donuts like the G78 15's, which we would then replace with BIG tires and fully-welded-steel white-spoke wheels for off-roading, when no serious off-roader would be seen with aluminum wheels, it's all a bit remarkable, eh?

[Ak Ron]

In my subaru with CVT I am more concerned with how the weight of my trailer will affect the rolling radius of the tires than wear. The CVT is sensitive to unequal tire sizes and weighting the two rear ones while unweighting the front seems potentially harmful. I don’t have a lot of tongue weight, so I only add a couple pounds to the rear tires. Nothing scientific. But measuring the static deflection as someone mentioned might be more exact.

[Wayne Collins]

Originally Posted by Ak Ron

In my subaru with CVT I am more concerned with how the weight of my trailer will affect the rolling radius of the tires than wear. The CVT is sensitive to unequal tire sizes and weighting the two rear ones while unweighting the front seems potentially harmful. I don’t have a lot of tongue weight, so I only add a couple pounds to the rear tires. Nothing scientific. But measuring the static deflection as someone mentioned might be more exact.

Is that an All Wheel Drive? I guess all Subarus are. Then I suppose it might care about RR.
Otherwise, with front wheel drive it shouldn't matter. We had a Highlander Hybrid CVT with electric drive to the rear axle. it worked just fine towing our Scamp 16.

[PatrickTXFL]

So looks like you got lots of help already and I skimmed through it. IMO when you have a TV with close to minimum specs I think it is a very good idea to have a tongue scale, or at least pay to have it weighed once. The what was factory tongue weight is usually not with propane or batteries loaded and certainly nothing in inside the RV or tanks. Better to know exactly what you have. Think hard about the cargo weight and what should be in the TV vs trailer to make things balanced to the best you can get. On tires I thought the defenders where great tires and if all things correct with your trailer weights I would run them at max rated tire pressure and if its your first go round with the rig I would say after 10 miles of towing pull over and give all the tires a good palm contact touch to be sure things are happy and not heating up. If you are in the summer heat somewhere might do another test, its easy to have a cold to hot pressure change of 5 lbs on a tire and good to know where your at. Other than when you can see an obvious squat beyond safe relatively new tires should be safe. I tire over 5 years old is not something I would set off on a cross country vacation towing a trailer of any size. Have fun be safe.