Simeon

Wow! I learned to drive in a 1988 (I think it was) Opel Ascona! With clear front turn signals that looked much better than the amber ones

It feels crazy that someone else even knows what that car is.

Simeon

As far as the start stop feature, I set the optional button on the steering wheel to turn the start/stop on and off. This way I can easily turn it off without having to find and press the button on the center console.

I usually turn it off when approaching a stop sign, for example, or coming to a stop where I know it will not be longer than a few seconds. But if I am coming to a stop at light that just turned red or one that is notoriously long, I'll turn it back on and it could make a relatively big difference on a shirt trip.

It may seem insignificant to you as one person, but think about millions of cars in LA alone saving 0.1 gal on their trip. That would be 100,000 gallons potentially saved in one day in one city. Multiply that by the nation and the world - it adds up quite a bit. Yes, percentage wise it is still a small number but it does make a difference.

cmoreau

I've always felt that a running engine is much more likely to continue running and get you to your destination than one that shuts off and has to start multiple times along your path. I've been fishing offshore and had a relatively new and reliable Yamaha engine fail to restart to come home (most people I fish with these days let the engines idle all day to prevent such a thing from happening and the friend I was with at the time has since adopted the same practice). Being 80-100 miles offshore and limping home on 1 engine instead of two still got us back, but we couldn't get on plane, it took us 3 times as long to get back and we burned ALL of the gas in the boat (second engine died of fuel starvation as we were pulling onto the trailer). It's a much different situation than driving a car around town, but that motor was running just fine until we shut it off. I'd rather be at my house, a store, or at my office when my vehicle decides not to start than at a redlight or in stop-and-go traffic on the highway.

I also work outside and it's hot enough here (Florida) in the summer that I don't want my air conditioning to ever stop blowing if I'm in the car. The comfort is well worth burning a little extra fuel.

PbCTTv8500

out of curiosity do you have onboard or out board engines and are the diesel?

cmoreau

They were 300hp Yamaha outboards. Gas

PbCTTv8500

If they are 2 stroke I had the same motor (single) on my first boat. Decent center console Boston Whaler. We all smoked a leafy substance at the time and I named it the Boston Inhaler

cmoreau

They were the latest, greatest 4-stroke motors at the time (2013 or 2014). Only about a year old when we had the issue though. I never asked my buddy what ended up being wrong with it, but he continued to run them for a few years until his new boat was built and arrived with triple Yamahas and a much bigger fuel tank. He hasn't had to limp home since.

PbCTTv8500

The only time I ever had an issue was when I accidentally left the ignition on and killed the battery. Took the cover off and everyone on the boat with shoes bathsuit strings whatever we had. Strung them together and somehow we pull started that giant engine to start. I want to say it was a 225 but I don’t remember. Also every single year someone would kick and crack the plastic oil storage tank. I finally got sick of replacing it and had a metal one fabricated.

I know have a Searay Sundance Diesel. Thank Jeebus this was a gift from a deceased family friend. I’d never be able to afford a boat this expensive.

I sold a cabin and some land and put the money into a savings account for the maintenance and running costs. It’s now my floating cabin at sea.

cathalferris

<Citation Needed> There's not enough pressure on the crankshaft bearings to expel *all* of the oil from the bearing. There's *always* enough of an oil film left to provide sufficient lubrication for the bearing for the very short space of time until the oil pressure builds up within a revolution. As for the cam lobes, their lubrication availability during a stop/start event is absolutely identical to that when normally running - again the oil is not fully expelled, and there's no hydrodynamic lubrication on that - there's no oilway feeding outwards from the highest pressure points on the lobe. It's fairly simple engineering knowledge.

I'm not disagreeing that there would be "more wear" I'm saying it's absolutely nowhere near as bad as you're making out. Another way of looking at this is how much screeching of metal on metal do you hear on normal cold startup, or during a stop/start restart? Proper engine oils are pretty good at maintaining film adhesion to the metal surfaces. As long as the engine is warm enough, and there's enough oil pressure before the start/stop event, the minute or so of being stopped is a relative non-event from a lubrication point of view.

I'm welcome to be corrected by a tribologist, but my years of engineering and mechanical experience would suggest that the reality of the situation in a stop/start event does not match your post's suggestion that there's no oil film present in bearings immediately after the engine stops..

wkearney99

Many of you seem to be living based on only ancient understanding of engine systems. Modern lubricants, starters, and surfaces are considerably better at handling start/stop than anything most of you grew up with.

Me, I turn it off because it's proven itself unsafe to me MORE THAN ONCE. Try having it enabled when you're creeping into a lane at the bank teller window. Several times the engine would cut off and left me without brake vacuum pressure. There wasn't room to use the accelerator to 'wake it up' so I had to put a tremendous amount of force on the brake to get it to stop, and while holding the brake, press the accelerator to get start/stop to wake TF back up again. I'm sure it was an 'edge case' where it assumed it was at a stop light, but I wasn't actually STOPPED just slowly creeping forward and it'll kill the engine. No thanks.

In regular driving I've only had it operate effectively a handful of times. It seems like my overall driving style just doesn't lend itself to start/stop functionality. Thus I had Vlad use my 958 as the test for his start/stop module. I've had it installed since and it's been completely effective.

VarioSpam

I find it quite annoying, mainly because it defaults back to being enabled every time you restart the car. A simple software change of making it retain the on/off setting would be fine. Reason being, I think it is good to turn the engine off at a red light if you know it is going to be a slow start and/or you aren't the first at the line. However, having it repeatedly stop / start in a traffic queue just drains the battery and hardly saves any fuel.
However, given that so many people report that their batteries last 10y, I wonder if having the cycling of the battery improves its health? (not sure this is a thing for lead-acid, I thought they were healthiest left fully charged..)

Trio

Not true with the 958.1 - or at least not with my '13. Push it once and it stays that way. I believe it changed with the 958.2 since the EPA started to only gave credit to the manufacturer if the system defaulted back to "enabled" with each ignition cycle.

wkearney99

Correct, for the later 958.2 it defaults to enabled.

This module listens to the bus and stores the active settings (more than just stop/start), and restores them after the next cold start: http://t-design9.com/memory_module_porsche.html

justabout

@cathalferris , here is a reference for some first principles regarding tribology, and based on your background you might find it enjoyable. I’m sure the manufacturers have tested these systems but I’ll wait for some real world data before I accept it.

othertbone

Hahaha because we are driving a Porsche lol