Team-BHP - Tips on driving an Automatic

Hi,

Quote:

Originally Posted by loving_alaap (Post 1226724)

Because >15 sec, switching off the engine is the best option (you have to out in P for starting again)

You can start in N (Neutral) also!

Quote:

Originally Posted by ImmortalZ (Post 1226797)

I'm not so sure on DSGs and CVTs. I suspect DSGs to be as efficient as manuals. CVTs, less efficient, although I do not know to what degree.

My average for almost 29500kms stands at 13.17kpl at the last fill over all conditions and with 100% AC.

In my case, it goes into the highest gearing at speeds of 60kph when the RPM shows 1500. Below that it shifts to a lower gearing. The problem is to maintain that RPM, as even a gentle pressure on the accelerator pushes the RPM to 1650 easily but the speed gain would be gradual.

Somebody else mentioned a 100kph speed at 2000RPM long back, but the best I could do was 80kph at 2000RPM.

In the US - most A/T cars are rated at the same EPA values as the M/T and I've even seen A/T cars being rated at HIGHER! These slushboxes have come a LOOONG way in the past 10 but I think the main reason is that there is no longer a difference of 1 gear. Most MTs were 5sp and autos were 4. Now with A/Ts 5 is standard, and 6 is common. BMW has 7 and Lexus has 8 gears!

CVTs are slightly better than regular A/Ts because they are able to maintain a lower engine RPM range especially under low load. However if you're constantly flooring it your mileage will drop like a stone since the engine will stay at its torque peak.

Quote:

Originally Posted by ImmortalZ (Post 1225214)

Unfortunately Thad, the DSG boxes are complicated beasts which have a high rate of failure in all of the VW implementations. I do not know how they hold up in the Ferrari and other manufacturers' cars.

DSG boxes are more manual than your average torque converter based auto boxes with planetary gear sets et al. I saw the warning about changing to neutral at lights when I was cruising through the Porsche 911 Turbo pages and I can't seem to find it anymore.

After driving the Civic AT (always, oh always in the S mode!) the Laura's DSG just blew me away with its responsiveness...its from another planet - felt it to be as good as/slightly better than manual shifting. Made Honda feel so shockingly poor in comparison!

Really wish VW/Skoda offers a 1 lakh KM/5 yr warranty on this beauty... That would help...

Quote:

Originally Posted by ImmortalZ (Post 1226797)

Slushboxes, which have torque converters are generally less efficient than their manual cousins...

Slushboxes! I like that! Excellent description that I never heard before. There are those moments of waiting for the hydraulics to catch up, when one thinks, "Go, for goodness sake, GO!". Both my Honda/Rover gearboxes were like that.

@Thad : Aw, it isn't my invention. I picked it up from somewhere on the Interwebs.

The DSG is a manual box, himan. It just has two clutches controlled by computers to offer you those near-instant shifts. Hondas have to make do with hydraulically actuated planetary gearsets which take eons to shift compared to DSGs.

@Atlblkz06 : The traffic here is so different from the US. I'm guessing our highway driving conditions are like your average city cruising and there are no freeways here to let our cars get their best averages. Someone here coaxed 16.7KMPL from his A/T Civic on some stretch of the GQ. I can't even think about those averages. The best I ever got was 12.2KMPL.

Quote:

Originally Posted by ImmortalZ (Post 1227534)

Someone here coaxed 16.7KMPL from his A/T Civic on some stretch of the GQ. I can't even think about those averages. The best I ever got was 12.2KMPL.

I maintain meticulous records regarding fueling and once had done 1,370 continuous kms with 90 litres with 15.2 kmpl.

My best was 16 kmpl over 700 kms.

I always fill full-tanks and the above results were achieved mostly on highways with speeds less than 74 kmph, AC mostly off, and some hypermiling techniques! :)

My overall kmpl is 11.04 over 37,825 kms with 3,427 litres over two years.

Quote:

Originally Posted by HappyWheels (Post 1225016)

Would not recommend movement to 'P' or 'R' when moving, definitely not to 'R' when in forward motion.

I was only talking of the forward gears and N.

In fact P is more dangerous. You risk breaking the park pawl (the pin in the transmission which locks the wheels. R is not recommended either but the R to L shift is sometimes used to get out when the car is stuck in snow, mud or sand.

Quote:

Originally Posted by Guna (Post 1224145)

Car may move in neutral if you are stopping on a slope. I normally put it to N and apply the parking brake if the red signal is going to be long.

thats exactly what i said before..i said you shift to N if you are using the brake/handbrake or P if your not.

Quote:

Originally Posted by revtech (Post 1224072)

1) .'N' if your pulling up the handbrake or pressing the brake pedal.'P' is the safest.no need to use the brakes and the car wont roll.

rev

Quote:

Originally Posted by thedreamcatcher (Post 1226712)

Guys, I want to know one thing. I have ended up in several arguments with my co-workers on this.

Is an automatic more fuel efficient than a manual or vice versa

By rule of thumb, manuals are more fuel efficient than ATs. The torque converter (fluid) has effeciency losses. This contributes to lowering the FE. Also, the AT gearboxes (but for CVT) are more heavier compared to the MT due to the additional clutches, actuators, etc... CVT wise, I am not sure if it is lighter or heavier.

Quote:

Originally Posted by trrk (Post 1226918)

You can start in N (Neutral) also!

Quote:

Originally Posted by loving_alaap (Post 1228272)

You can start an AT car (atleast OHC) only in P.

trrk is right.you can start an automatic in N or P.however it would crank in any other gear for obvious reasons.

rev

Hi,

Quote:

Originally Posted by revtech (Post 1228616)

trrk is right.you can start an automatic in N or P.however it would crank in any other gear for obvious reasons.
rev

Thanks, revtech!

Quote:

Originally Posted by loving_alaap (Post 1228272)

You can start an AT car (atleast OHC) only in P.

I have confirmed that it indeed starts in N.

Quote:

Originally Posted by manim (Post 1227959)

See? Your figures make me cringe. My average KMPL over 5800KM is just 9.11KMPL.

Then again, if I actually placed sane loads on the car, traveled at sane speeds, I might get better averages. Then again, I'm insane :Frustrati.

The torque converter does lead to a 15% or so of loss in consumption. However, many new ATs have a torque converter lock up which as the name implies locks up the TQ at speeds above a preset. These are to be found in most higher end cars - the new City also has it. Further, some boxes like the DSG are esseentially manuals with automatic gear selection, and are even more efficient (losses in the 5-10% region).

One thing though to keep in mind - in start-stop traffic the fuel consumption is more dependent on the time rather than distance.

Quote:

Originally Posted by revtech (Post 1228616)

trrk is right.you can start an automatic in N or P.however it would crank in any other gear for obvious reasons.

rev

i jus read my post and i want to rephrase it as

you can start an automatic in N or P.however it wouldnt crank in any other gear for obvious reasons.

rev