Article in the NY Times...
http://www.nytimes.com/2016/04/08/au...it-or-not.html


I use dynamic most of the time, so start/stop is off. But my other car is a hybrid, so I'm used to the engine starting/stopping in that. Though it's less obvious than in the Jag.

 

Initially, I was adamantly opposed start-stop feature. Now, I just grew to simply dislike it. Fortunately, with a MT I can control it to a large extent - if I keep the car in gear and clutch in, it won't shut off.

My objections to start-stop feature as follows:

1. It will shut off engine before its fully warmed up
2. It is not seamless, when it restarts I can often feel idle more prominently
3. It isn't intelligent enough to determine when you are pausing in traffic, and when you are stopped at the light and not likely to resume moving. Despite the car having back and front sensors that could be used to know if you wills tart moving shortly.

I drove hybrid loaner in the past, when you can go electric-only mode start-stop feature makes sense. Not in other circumstances.

 

At the same time F-type fuel economy is absolutely abysmal. I am getting 20MPG in mixed driving. I had similar gas mileage with late 90s Mercedes and BMW V8s. Surely, they could do better today.

At the same time, who cares? This isn't a Prius.

 

I get more like mid 20s, but that's probably expected with the 8-speed. And those of us who have checked have determined the trip computer is about 2mpg high.


I was interested that the article mentioned 9- and 10-speed transmissions. I would think at some point a CVT makes more sense. Have one in my hybrid, and think it's great in that application. Can't see one in an F-type, however - wouldn't be right.

 

I don't think they yet developed CVTs that could handle lots of power. I also agree - 10 speed makes no sense. All that constant shifting will make long-term reliability questionable.

 

I was wondering when this was going to come up. 20 is pretty damn good for the performance that we get. My wife's C63 is a bit worse for less performance and our previous CTS-V always pulled to the right when passing a gas station. On a long trip on a really good day with a tail wind it got 20.

But you're right. Who cares? I didn't buy this car to worry about being able to afford to fuel it.

 

There was a time when people said 4-speed transmissions made no sense, then it was 6,7, and 8 speeds. Who knows what the continual push for reduced emissions will bring.

At some point, when electric cars reach a higher percentage on the streets, people will wake up to the fact that they aren't really "clean" at all, since the vast majority of them are currently powered by coal-fired power plants. The primary fuel source for the U.S. power grid will have to be completely revamped to make them actually clean.

 

A bit of defense here for electrics. Even though they are fueled by coal, the pollution is centralized at the power plant which makes it easier to deal with. Not saying that we are dealing with it effectively, just that we could.

 

I disabled mine per other posts and had forgotten all about it until I saw this thread.

 

Still not sure what's so difficult about turning the switch off...it's the very first thing I do after pressing the start button.

 

Hate it and turn it off anytime I'm not in Dynamic. I could give a rats azz about the fuel economy though I think that 20 mpg is very good.....my other 500hp car gets between 6 and 8mpg....don't care about that either.


Cheers,
Dave

 

It's a system that drives me crazy. It is just too dumb and it's far from seamless. To hear JLR tell it, you barely even perceive it happening. False.

 

+1. This is the first car I've had with ECO. Given the controllability offered with the MT (just depressing the clutch, lightening pressure on brake, putting light radial pressure on the steering wheel), the ECO feature is not intrusive to me at all and I enjoy saving shekels when I can.

 

Exactly.

I personally don't have a problem with it. The only thing that I wish was different would be allowing the car to be fully warmed up before the ECO mode kicks in. Other than that it works flawlessly.

Compared to my Audi Q5, the F-type has a faster restart and far more responsive. With the Audi it seems like it is always delayed for a second. With the F-Type as soon as you depress the clutch it starts up right away.

 

Now. If our cars were to use small turbofans as the power source in a hybrid drive system - aside from the differences in the noise - would we care provided the performance was the same???

Stand next to an M1 as it powers up, and tell me that isn't a good sound...

 

I've often wondered if a small turbine driving a generator, mated to electric drive, wouldn't make for a decent automotive platform. Not to be confused with the old turbine cars.



Are you referring to an M1 Abrams tank? That has a nice turbine. And no, I've not been near one when it fires up.

 

CVTs are horrible. They take all the fun out of the car, they don't hold up and when one of the "rubber bands" inside one breaks they have to replace the entire transmission. Now I'm biased because it was exactly what happened to my sons Maxima. Nissan even had to extend the warranty on the transmissions to 125,000 miles because of all the failures. No I suppose there might be better CVTs out there but I don't ever want another one.

 

The stop start can be disabled so it will not work at all. Mine never worked and they found a wire that was not attached to the battery terminal so now it stops and starts as designed. Not that I wanted it but was concerned about what else was not working correctly.

There are two wires attached to the right side (passenger) of the battery on the XF and the smaller one controlled the stop start. That is on the 2016 XF anyway.

 

Yep, the very first thing I did on my F-Type when I got it home was to permanently disable the stop/start system by disconnecting the positive lead to the secondary battery.
Yes, I know I could simply hit the "Eco" button every time I started it up, but therein lies the clue - every time, what a PITA!

 

One thing that concerns me about auto stop/start is the long term effect on engine wear. I was always taught that the vast majority of engine wear takes place at startup - obviously as there's no oil pressure.

A while back, I actually counted the number of auto stop/starts the car made on a route I regularly take. It was 17. So that's 17 non-pressurized starts on a journey that would normally have just one. If you extend this out over a number of years and tens of thousands of miles, the number is huge.

I don't know all the technical justifications for the ability to have auto stop/start these days, but I guess that latest spec oils have the ability to cling to parts better, and engine tolerances are tighter than they used to be. Maybe this helps negate the wear effects of non-pressurized engine starts. Maybe the engine has a function to help hold oil pressure in an auto stop/start situation.

It's very nice to have improved fuel economy, but at what longer-term price? JLR will love the immediate benefits to them in marketing and corporate wide average fuel efficiency - what do they really care about the longer term reliability effect for customers?

I keep mine turned off, and its now a "muscle memory" type thing as part of my start procedure. Apart from the technical justifications I tussle with, every time the engine stopped unexpectedly (to me), it freaked me out. I've had too many cars over the years where a surprise cut-out was only a bad thing. Of course many of them had Lucas electrics!