Autostart - Pulling the bucks from our pockets?

[old man emu]

One of those environment-saving innovations in modern ICEs is the Autostart. It's function is to stop your engine so it doesn't idle while you are stopped at traffic lights. The claim is that it reduces fuel consumption and, as a side product, reduces exhaust gas pollution. But do the savings from reduced fuel consumption match the mechanical downsides? 

 

And stop sniggering you EV drivers!

 

 

[facthunter]

Are  we going to get all the crap from U tube?  Of course it cuts pollution and the restart is instant. You can disable it easily if you wish to. It will never be introduced to aircraft engines. IF your engine doesn't idle reliably, it's unserviceable. You check it when taxiing don't you?  Nev

[old man emu]

57 minutes ago, facthunter said:

Of course it cuts pollution and the restart is instant.

I agree with that, but the point being made in the video is the wear and tear on parts that are not used many times during a journey, such as the starter and starter ring gear. 

 

59 minutes ago, facthunter said:

IF your engine doesn't idle reliably, it's unserviceable.

Too true! And when it idles smoothly, it doesn't move on its mounts to the degree (albeit slightly) that it does when starting. Every start adds to the deterioration of the engine mounts, whether that's one start at the beginning of a long, sustained journey, or many starts driving in urban traffic.

[facthunter]

I don't know of any great rush to the Auto electricians for starter matters. Ther's room for improvement on most starters just make them a bit better and al will be well.  Some delivery Vans get extensive use of starters and as I said the start is so soft and instant you don't even notice it. The protection of the button not working IF the motor is already running would save some ring gears. You just press it and don't hold it on. If the motor is running pressing it again will not do any damage  Nev

[facthunter]

 The load on the engine Mounts depends on the skill of the. operator as to how much throttle is applied. The starter is always mounted on the engine. A backfire would load the engine Mounts. So does doing aerobatics. Gyroscopic Precession, Thrust,"P" factor  and "G".   Nev

[onetrack]

Starters are cheap, compared to the fuel savings. Todays planetary and outside geared reduction starters (PLGR & OSGR) have softer flywheel ring gear engagement events, than direct drive starters. Flywheel ring gears take a long time to wear out, but keeping a wonky starter in use, instead of replacing it, is a good way to shorten ring gear life.

I don't know that the additional amount of starting events is going to reduce engine mount life all that much - but if it does, engine mounts are easy enough to replace, and generally not too expensive (unless they're the fluid-filled type, which adds cost).

A lot of people don't understand that clutch shudder on takeoff is often caused by deteriorated engine mounts - and the removal of asbestos from clutch linings contributed to an increase in clutch shudder problems.

I guess not a lot of people are affected by clutch shudder today, as around 80% of vehicles today have automatic transmission.

 

My 2013 diesel Hilux is starting to suffer from clutch shudder at 130,000 kms, it only does it when cold, for the first few takeoffs, but it's annoying, and I'll have to inspect the engine mounts to see if there's any deterioration there.

My Hilux doesn't have any engine auto stop/start feature, but I regularly shut the engine off at the lights if I have to wait for multiple light changes and slow traffic light changes. I'm still on the original starter, and it shows no sign of deterioration.

 

https://www.roadrunner-starters.com/pages/starter-motors-a-brief-history-lesson

 

Edited August 25 by onetrack
added link...

[willedoo]

I often chuck mine into angel gear going down hills. Go downhill on idle instead of revving it's head off.

[onetrack]

Yes, I do that too, in hilly country. I'd like to think I'm saving fuel, but I think the fuel savings are minimal, I expect the engine wear level is reduced.

 

I've just done a wheel swap on my N70 series 2WD Hilux, it had 205/70R15's from the factory and I believe the ute was under-tyred - and the engine was pulling 2600RPM at 110kmh, which I reckon is too fast.

Once I go much over 2500RPM, the fuel consumption seems to increase disproportionately. I've always believed that diesels do best on fuel at a maximum of 2200-2400RPM.

 

So I rounded up a full set of wheels and tyres from a later N80 series (2015-2018) 2WD Hilux, which are 215/65R16's. They fit straight on to the N70 series, the PCD and rim offset are identical.

There's about a 3.7% increase in gearing by using the bigger wheels. I was hoping this would improve fuel consumption by reducing engine speed a bit.

 

However, I was quite amazed at the improvement in overall performance - apart from a barely-noticeable reduction in acceleration, the Hilux now feels like a completely different vehicle.

It rides and handles better, engine speed and noise is down, and I'm convinced there's been an improvement in fuel consumption. 

 

I know the wheel changes affects the speedo reading, but I measured the speedo at 110kmh using a GPS app on my phone, and it's now showing 110kmh at 108kmh, so it must have been out by at least 5% on the original wheels.

The best part was, I picked up a full set of unwanted N80 Hilux wheels (from a car yard, of all places!) for $300, and the tyres were all between 65% and 90% tread! So I made a double gain for a relatively small financial outlay.

[spenaroo]

I plugged an OBD reader into my car chasing a fault the other day,

and had its "dashboard" up on my phone while driving. was surprised to see the difference between the OBD speed reading and the actual speedo reading about 5 under.

[old man emu]

You will find that the displayed speed is less than a speed determined by GPS. My conspiracy theory has it that manufacturers set their speedometers up like that so they can't be drawn into speeding offence matters. While it's not a bad thing, it does annoy when someone is driving using a speed display that has been authenticated by a GPS that is independent of the vehicle's GPS. I've checked my speedo against a couple of GPS devices but cross reference the GPS speed to my tacho. Since I'm driving on highways at a constant speed I simply set 2500 RPM to give me 100 kph on cruise control. I've also checked my speed by time/distance and at 2500 RPM constantly take 6 minutes to travel 10 kms (100 kph).

 

In town, I revert to the car's speedo and take advantage of the manufacturer's over-reading speedometer.

 

The annoyance I have with over-reading speedometers is the good people who drive at 100 kph indicated, but are actually only doing about 95 kph. When you've got lots of distance to cover, you don't want to be sitting behind them.

[octave]

https://rac.com.au/car-motoring/info/car-doctor/speed#:~:text=The Australian Design Rules require,speed indicated by the speedo.

 

Theoretically, GPS can be very accurate; however in practice GPS accuracy can vary depending on variables such as the terrain of the area you’re driving through, the presence of tall buildings, weather conditions, electrical interference and the number of satellites available to the GPS system (a minimum of three, preferably four).

 

The Australian Design Rules require that a vehicle’s speedo must not indicate a speed less than the vehicle’s true speed or a speed greater than the vehicle’s true speed by an amount more than 10 per cent plus 4 km/h.

 

This means that the vehicle’s true speed must not be higher than the speed indicated by the speedo. That is, at a true vehicle speed of 100km/h, the speedo must read between 100km/h and 114km/h. An alternative way to look at it is; at an indicated speed of 100km/h, the vehicle’s true speed must be between 86 km/h and 100km/h. Generally speaking, on modern cars the true speed is only a few km/h less that the indicated speed.