Tires and mileage

I had a set of the "Fuel Economy" set of tires on my car once.
I am glad to see the back of them.
I cot more grumbles from my ABS when using them than any other tyre I ever owned?.

The thing is they have "Less rolling resistance"... yep, thats the one.
But what that means is you sacrifice traction for fuel efficiency.
That by the way is not a myth, although, for the reasons of being shown on teevee, you can say it is, but, we know the truth here?.
If you have less rolling resistance, you have less resistance all the time, which is less traction under either acceleration or braking.

To test, set a vehicle in motion that has ABS to a set speed, and at a marked line, dynamite the brakes and see how long it takes to stop. More speed will mean a greater difference in stopping, so try at "freeway" speeds to show a greater difference.
You need to use new tyres of both usual variety and fuel economy variety.
Measure that in feet.
Repeat three or four times to allow variance in road surfaces.
Swap tyres.
The difference between fuel economy tires and grip tyres will be obvious in feet taken to brake to a stop.

You may also repeat using bot Radial and cross ply, then for education sake, show why "Off road" tyres dont have as much grip on tarmac as tarmac tyres, then carry on and show treaded tyres against "black snot" hot sticky properly warmed up racing tyres, then snow tyres against all season tyres against summer tyres, then repeat all of that again in wet sloppy greasy conditions.

One of my early jobs was one day supplying tyres to a racing team, a whole container of tyres, of all different compounds, for a Rally Cross WRX race weekend.
I Got an education in tyres right there and then when my eyebrows shot up all the way to the top like chapel hat pegs after being told this was probably all for one race for ONE vehicle....[ that team being in close competition for the top position...]
The weekends stages were part snow part grit part tarmac and also chances of rain.
They needed options for wet or dry for grit gravel or tarmac, for snow, for that stage if the snow melted, options for tarmac wet or dry and again in case there had been snow, and all that again wet or dry for the gravel/grit stages.
They also needed to plan that after just one stage the vehicle may return with no working tyres because punctures, or just worn out after just one stage. There were three stages, each one to be run in both directions, making six runs in all, and the planned on changing tyres each time the car stopped. You have max 20 mis fettling time after each stage, thats mechanicking to the stop watch, pit stop on a LOT of caffeine, you choose what parts of the car need attention most, and how many spanners you can get around that car at one time.
And then, my return journey, all used tyres were sent back to the manufacturers for evaluation to further their R&D on the compounds used. I was talking to one of the pit crew for about an hour, lunch break, although he didnt of course reveal trade secrets, he was quite happy to chat about many things I didnt know.

Yeah, I had no idea the amount of engineering that went into tyres.

I like the dynamometer study, force in minus force out gives a very good efficiency number, and being able to show thermal losses gives a very good illustration of waste energy being turned into heat.

is there a direct connection between efficiency and grip? I'm not so sure. if you lose too much grip, it takes the efficiency right with it, does it not? a "does tread make a difference in traction?" thread might be in order. which is not to say there isn't a point at which you sacrifice grip for efficiency. there's a reason why steel wheels on steel track let trains move goods very efficiently. but accelerate and decelerate more gently than race cars.

the other thing my father has said is that one brand of tires rolls more smoothly than another brand with similar tread patterns. mind you, this is not saying that touring tires roll more smoothly than mud tires. this is saying that (squawk) brand touring tires roll more smoothly than (bleep) brand touring tires.

as for putting nitrogen into tires because it behaves more consistently than putting atmosphere into tires, people agree that the science is valid, but debate over whether that makes a difference for the average driver.

Not sure if the RC test would tell you anything useful as the tires probably aren't even close to real tires. The track test would really be the unquestionable proof as well as give an indication of ride and handling.

Or have the dyno visit you?.
There are now mobile Dyno's built on the back of a truck bed that can be taken to track days and car shows that allows people to run what they brung and see exactly how many horses have escaped on older engines or see how many the air scoop has caught on re-built and "Improved" engines.

Getting hold of one of them in the "closed season", ie Over Winter after all the car shows have finished, could be done more easily if it provides exposure for "Daves Dyno" on the show.... and more in budget that having to go find and book space on a busy commercial dyno.

However.
As most vehicles are strapped down during the test, will that show the amount of grip you have, because the strapping down its self is an artificial grip?.

This is where I get a bit pedantic with those that claim "My engine has 1,000 horses", and then bang on incessantly about the shape of the cam-shaft, the type of cylinder head, and all that, but, they cant tell you how many at the wheel.
The Transmission for you Americans or Gear Box for the rest of the world steals some of those horses to make the cogs turn, the axles, differential, wheels and tyres all take their share, and then you have the fact that their car is as aerodynamic as a house brick turned sideways, sho am I to complain with a 900 horse engine and a "!Cab over" style truck thats the whole side of a house sized?.
But then at least all 900 horses I have can be directed towards the road without me leaving half a tyre per mile in double black lines?
The Dyno will tell you how may horses you have that can get transmitted to the wheel, and that is good.
But what we are missing here is how many of those horses are being used per mile "Safely" when the car is in use on the road.
It will tell us straight line speed, but, even you Americans in your cars that dont do corners, [/sarcasm] as the heads on TG will tell us, it doesnt tell us normal road use, which is corners, braking, acceleration.
I dont know if you realise it but a change in tyre alters subtly the way you drive?.
Just as a change in car should, in that you learn within about half a dozen corners how a different car brakes, all the way up to your Spongbob you drive TLW, and many are different, some you know dont like to brake mid corner, some will go round corners like they are on rails, brake or no brake, which I have to say most Toyota's I have driven excel at for such mass produced vehicles, some are more eager to stop, well, your tyres, and a change in tyre, can alter that.
I notice my tyres starting to wear by when I pull out of the top of the road.
Its a sharp~ish corner to a 40 speed limit, so if you see a gap, you "nail it", or you will be waiting for the next ice age at times, and if I do that when my tyres start to wear down, the inside of the corner tyre "lifts"?. As in looses traction and spins slightly...^{This happens about 2.0 to 1.6 mil on tyre depth, still fully legal, but at 1.8 I start to plan replacement before the next Big White.}
Reason I gave up on the hyper-mile economy tyre?. I lost traction quickly with them, I HAD to drive more gently, because I didnt have the grip...
Therefore, I was almost driving "Hyper-mile" style...
Good?.
Nope.
I need a tyre that stops me from 20 in the length of an eye blink when a kid on a bike doesnt look.
And you may remember that happened not that long back to me.
Would that tyre choice have made a difference?. Thank the lord duck I never had to find out....

Yes, Run the Dyno, but I would like to see the brake test done at the same time to show that as an educational tool.
Especially the bit "In the wet"... that may scare some people into driving more sensibly when it rains, and that has to be good, yes?.

Keep in mind, I have driven American cars, and cornering ability is bad when compared to our own here in UK.
Which is why we dont like live axle suspension and favour all round independent suspension, dont go for leaf springs but have coil over dampers, and cornering ability is more important than any straight line ability, therefore we dont do a lot of drag racing, unless Drag racing is a couple of queens in high heels trying to get to the bar before last orders?.
Which by the way is highly entertaining when they already had a few diesel injections.

If you want all out cornering ability, take a look at what we can do with the FX4 series of London Black cabs.
The can turn on a sixpence and give you 5p change in metric or old money, almost not much more than three times their own width in a turning radius.

Cornering ability here in UK and the wider europe, is not a "Bonus", its more a basic ability, and cornering at speed more than walking pace is a MUST, I have never ridden a bike that had to do a 3-point turn on a two lane road until I borrowed a Hardly Drivable, and the one time I drove an old ford Mustang, the lack of turning radius astounded me. There was the one time I had to do a 3point turn on a "mini" roundabout?.. [thats one of them painted on in white paint things...]

You may not realise it, but cars built for your "Wide open space" roads in US, are almost painful to drive around european roads, and sometimes impossible to drive around older Roman architecture towns and cities.
More so when you get to the older 50's 60's style "Land yacht's" of Cadillacs and the like.

Show that again with my last bike if you can find one Ducati 907ie, note that on that vid, at several points, he is "almost" scraping the exhaust, the Duke will get so low you can not just touch the floor with hand and elbows, it has you screaming how the hell do you get that kind of grip off the sidewall of a tyre.

When you break loose a sports bike, if your that daft and try to hard, it either regains grip or it doesnt, if it doesnt, kick it and slide, if it does "High side".

That vid with the harley, until he broke grip with the rear tyre, most of those corners wouldnt even cause me to drop a cog on my old Duke, those aint corners, thems just slight bends.

It isnt all about speed either, most bikes I have had can make a U turn at low speed in a single lane road without hitting either kerb, rider skill can do that without putting your foot down, but it makes it easier parking up, and no bike I have ever owned came fitted with a reverse gear, although I have ridden Goldwing Aspencade, 1500 engine, you need a reverse on that beast.
I know some harleys dont need reverse, but the bigger ones do, and they dont get a turning circle as good as my current car.

But this wasnt all about Bikes, it was the general discussion, our roads have less space and tighter turns that American ones, including that one with the hairpins on a hill you have in SF. which you may see as extreme...
In truth, that one in SF is probably about Normal on those turns for some of our roads, in that we do have tighter, but not that often.
Most bikes I have had could manage that as a hill climb at a reckless speed, and most times, wreck-less as well, we have speed bumps bigger than that over here?.
Some may call those speed bumps the hills of Wales, but I see them as a challenge.
But back to what I am challenging, european and UK cars have better turning ability in general than most US cars, I know its a PITA, but one I know you have got, as an example, the Toyota Prius, thats about average for a larger family affordable sized vehicle in UK.
We have smaller, the Golf, maybe you know it as the Rabbit?. thats a average 5seat family car for smaller people in UK.
Even that can turn on a sixpence and give you change when compared to the radius of say a Mustang.
Unless you light up the tyres that is... Golf are FWD, useless at power sliding.
I can drive one, but the drivers seat is so far back with me in it you wont get anyone behind me comfortably....
But they are a lot of fun if fettled correctly.

You have more space than us, and quite often, better roads as well, we have to manage with a right mess of roads built for horse and cart that used to make a chicane if there was a tree in the way, and in some places, went around bigger houses if the cost of a straight line was too much in demolishing the house.
We didnt plan our roads, they started as sheep tracks, and in some places, the harder ground around boggy areas?.
Most just happened, and some have been there since stone age times.

I agree with the tyres thing, too hard, you nmeed to warm them up to get grip, and they are great at lasting long, but dont give you the grip, too soft, you waste energy in rolling resistance, but sure as heck they grip like black snot round the tight stuff.
This is why Wagon tyres are hard, and sports vehicles prefer racing compound.