Falling MPG any ideas?

Norman_Castle

Herzlos wrote: »

It can't detect the sudden increase in diameter; it only knows how fast it is spinning. It might notice that one has changed in relation to the others but that means it's only work if you replaced tyres one at a time.

All I can do is identify that suddenly one of the wheels has spinning faster, which indicates that it's radius has reduced and is likely punctured.

It's not capable of wear monitoring without some additional input on distance travelled, and that'd either need some ground facing camera calculating how fast the ground is passing, or super accurate GPS.

The system recognises regular journeys from stop/start/speed patterns, and compares actual wheel revolutions with expected wheel revolutions. If there is a decrease in revolutions for a known journey it knows the distance has remained constant so by default the tyre size must have changed.

mcpitman

Norman_Castle wrote: »

The system recognises regular journeys from stop/start/speed patterns, and compares actual wheel revolutions with expected wheel revolutions. If there is a decrease in revolutions for a known journey it knows the distance has remained constant so by default the tyre size must have changed.

Is the car brand these are installed on a secret?

BeenThroughItAll

Norman_Castle wrote: »

The system recognises regular journeys from stop/start/speed patterns, and compares actual wheel revolutions with expected wheel revolutions. If there is a decrease in revolutions for a known journey it knows the distance has remained constant so by default the tyre size must have changed.

To be fair, this is starting to sound far more theoretical than marketable.


I too would now love to know what I can buy that actually has this system on, as I can't find any references to it anywhere other than here.

Strider590

Norman_Castle wrote: »

The system recognises regular journeys from stop/start/speed patterns, and compares actual wheel revolutions with expected wheel revolutions. If there is a decrease in revolutions for a known journey it knows the distance has remained constant so by default the tyre size must have changed.

That's great until we get snow or the driver does lots of wheel spins, at which point I would assume your screwed? Unless you make a point of always accurately wheel spinning a set number of revolutions on every journey.......

Mr_Mink

Ok so a quick update. On the air filter front I cannot find the service documents (think I've filed them away too safely) so will just call the dealership to ask when the air filter gets/has been done.

I tried the old Italian tune up on Tuesday, got home with a slightly higher mpg on the display. Yesterday morning was evil traffic so it dropped to 49.8. Drove home normally and was at 49.9.

This morning I turned on the Think Blue malarky which gives a visual display of gear changes, acceleration and braking. Was keeping that as happy as possible, hit no traffic at all and thought wahey, checked the trip computer when I got to the office... 49.9.

Thinking maybe a bit of Redex type stuff to see if that helps.

BeenThroughItAll

Mr_Mink wrote: »

Ok so a quick update. On the air filter front I cannot find the service documents (think I've filed them away too safely) so will just call the dealership to ask when the air filter gets/has been done.

I tried the old Italian tune up on Tuesday, got home with a slightly higher mpg on the display. Yesterday morning was evil traffic so it dropped to 49.8. Drove home normally and was at 49.9.

This morning I turned on the Think Blue malarky which gives a visual display of gear changes, acceleration and braking. Was keeping that as happy as possible, hit no traffic at all and thought wahey, checked the trip computer when I got to the office... 49.9.

Thinking maybe a bit of Redex type stuff to see if that helps.

The dealership will tell you whatever it says on their service system as when the filter should have been changed. That in no way shape or form means it's actually been done, however. Dealers have been known to 'forget' invisible items like air filters which look OK when 'inspected'.


For the price of a filter and ease of changing it, I'd buy one and pop it in. Eurocarparts will no doubt be able to sell you one cheaply.


While you're in ECP, pick up a bottle of their Normfest injector cleaner. I've been using it in my cars and bikes for a few weeks, and it's definitely smoothed out the slightly lumpy idle from my wife's Saab, and lessened the vibration I get from my BMW bike at >5000RPM. Cheaper than many of the others too.

Norman_Castle

mcpitman wrote: »

Is the car brand these are installed on a secret?

Its not on any specific brand. Its just the fuel computer using information fron the ABS sensors. Nothing needs to be installed other than computer software.

mcpitman

Norman_Castle wrote: »

Its not on any specific brand. Its just the fuel computer using information fron the ABS sensors. Nothing needs to be installed other than computer software.

So it's not currently installed to any marketplace cars but could be (in theory)?

Herzlos

Norman_Castle wrote: »

The system recognises regular journeys from stop/start/speed patterns, and compares actual wheel revolutions with expected wheel revolutions. If there is a decrease in revolutions for a known journey it knows the distance has remained constant so by default the tyre size must have changed.

I don't see how it can go that. stop/start/speed patterns aren't unique enough to identify a particular road or driving line, and the only information it's getting is on how far the wheels rotate over a given journey, so will itself be skewed by the tyre wear. It can maybe do it via GPS but it'd either require a constant high speed or super-accurate GPS to notice a meaningful distance in the rotation:distance ratio.

It's probably accurate enough to have a set of service intervals for each tyre, that asks to you check them after 10,000 miles. Maybe knock a few miles off for each wheelspin/emergency stop.

But none of that replaces actually looking at the tyres anyway as there's unlikely to be reliable sidewall/tear damage detection.

JustinR1979

BeenThroughItAll wrote: »

While you're in ECP, pick up a bottle of their Normfest injector cleaner. I've been using it in my cars and bikes for a few weeks, and it's definitely smoothed out the slightly lumpy idle from my wife's Saab, and lessened the vibration I get from my BMW bike at >5000RPM. Cheaper than many of the others too.

At last check, stp in a silver bottle was the only one with a chemical that did any good, can't remember it's name.
Was a few years ago now, so one you mention (and maybe others) may actually have an additive that works