Does any manufacturer quote its vehicles' minimum tow force required ?

This criterea is an important part of efficiency ; directly affects
vehicles' mpg, should be disclosed as required by law.
i] brake bind : e.g. my 1985 Nissan Sunny 130Y assembled in msia
had springs fitted in a wrong way ( the springs force idle brake pads
onto brake discs ), so the front wheels could barely spin before I
removed these stupid springs.
ii] size / height of tyres : the taller is a tyre, the lower will be the min
tow force needed to overcome the same brake bind, so cheapo cars
with short tyres will need a higher min tow force.
iii] toe-in : e.g. my 1990 honda accord's prescribed rear wheels' toe-in
kept rolling resistance very high, before I ignored these toe-in.
iv] low rolling resistance tyres : e.g. Michelin's "green" tyres have lower
rr than Goodyear / Dunlop 's. So if a vehicle has cheap tyres with
high rr, then its specification should reveal a higher min tow force
required.
v] lubricant in wheel bearing : now modern lubricants ( e.g. synthetic
oil / fullerene / semi-paraffin ) can be 2x as slippery as grease, so if
a manufacturer still puts cheapo grease into bearings, this would
cause a higher min tow force.
vi] nitrogen in tyres : will significantly reduce rr esp for big / high
profile tyres ( like lorries' ). So manufacturers should not be allowed
to ignore this fact, @ the expense of mpg & consumers' CO2
discharge.

TE Cheah wrote:
> This criterea is an important part of efficiency ; directly affects
> vehicles' mpg, should be disclosed as required by law.
> i] brake bind : e.g. my 1985 Nissan Sunny 130Y assembled in msia
> had springs fitted in a wrong way ( the springs force idle brake pads
> onto brake discs ), so the front wheels could barely spin before I
> removed these stupid springs.

Not sure how disclosure of the minimum tow force required would help
you with this problem.

It's been my experience that as a group car have much lower rolling
resistance than 30 years ago. They also offer lower wind resistance,
which is in my mind a bigger component of milage.

> ii] size / height of tyres : the taller is a tyre, the lower will be the min
> tow force needed to overcome the same brake bind, so cheapo cars
> with short tyres will need a higher min tow force.

Don't forget to factor in the added inertia of a larger wheel.

> iii] toe-in : e.g. my 1990 honda accord's prescribed rear wheels' toe-in
> kept rolling resistance very high, before I ignored these toe-in.

It's a tradeoff between keeping the car moving in a line, tire wear and
rolling resistance - nothing new. Unless you know something about
suspension geometery I would not fiddle with the recommended settings.


> iv] low rolling resistance tyres : e.g. Michelin's "green" tyres have lower
> rr than Goodyear / Dunlop 's. So if a vehicle has cheap tyres with
> high rr, then its specification should reveal a higher min tow force
> required.

True, but not new news. Any tire represents a tradoff betweel tire
wear, adhesion, rolling resistance, etc. I'm sure a tire-smith could
construct a tire with very low rolling resistance, but you would
probably not like its driving characteristics. One can easily reduce
rolling resistance by pumping the pressure to the the highest
recommended level.

> v] lubricant in wheel bearing : now modern lubricants ( e.g. synthetic
> oil / fullerene / semi-paraffin ) can be 2x as slippery as grease, so if
> a manufacturer still puts cheapo grease into bearings, this would
> cause a higher min tow force.

Possibly...but I'm not concerned.

> vi] nitrogen in tyres : will significantly reduce rr esp for big / high
> profile tyres ( like lorries' ). So manufacturers should not be allowed
> to ignore this fact, @ the expense of mpg & consumers' CO2
> discharge.

And you are recommending what in particular?

One has to factor into the analysis the cost of inflating tires with
nitrogen vs air...the cost/benefit may end up a lot closer.