VWAR Old forum !

Technical => Technical => Topic started by: tisseman on April 25, 2004, 05:39:35 PM

Title: fuel consumption
Post by: tisseman on April 25, 2004, 05:39:35 PM
I am intrested of the fuel consumption of VW with autostick compared with manual?
I have not any car VW with autostick but I have a bike with autostick.
I built from scratch a bike with VW engine and manual gearbox and it was registrated in 1995, but this winter I change the gearbox to autostick from a heavy damaged VW -72 at the yankyard. The gearbox is rebuilt to fit the bike and it works just fine. But I have not figure out how mutch more fuel it takes compared with manual.
In a car how mutch more fuel it takes compared to a manual?

link to the bike:
http://hem.passagen.se/matisse/Engelska/EMC.HTM//Janne%20in%20Sweden
Title: fuel consumption
Post by: bookwus on April 25, 2004, 09:30:55 PM
Hiya Tisseman,

There are so many factors involved when it comes to calculating fuel consumption that the best anyone can do is to come up with a rough number.  For example, what kind of fuel are you using?  What are your driving habits?  How is your vehicle equipped?  What sort of driving do you do?  All of these factors can and do influence fuel economy.

But, to more or less give you an answer to your question......   These should be no big difference between a manual and an AutoStick in terms of gas mileage.  This assumes that all those other factors (some of which are mentioned above) are equal.

And this.....  I drive my AutoStick Bug to work every day (yes, usually Saturdays and Sundays also) a round-trip distance of 15 miles for a total of 210 miles every two weeks.  I fill it up every two weeks and it takes 8 gallons plus or minus.  That works out to about 26 miles per gallon.

Mike

1970 AS Bug
Title: fuel consumption
Post by: Cobey on June 07, 2005, 08:52:45 PM
Hey Mike, what is your driving method/style?  I've been trying to see what is the most fuel economic style.  e.g.  Running 1st up to about 35-40 then going into 2nd, except for merging onto a highway.
Title: fuel consumption
Post by: bookwus on June 09, 2005, 01:39:01 AM
Hiya Cobey,

Generally, I run it through the ranges when I drive.  However, I rarely get into Second Range because 90% of my driving is on surface streets to and from work.  My top speed during a commute is no higher than 45 mph.

When I do shift up I pay attention to the speedo tick marks for shifting.  I usually shift from Low Range into First at 30 to 32 mph.  First into Second at 46 mph.

Shifting down is more a matter of listening to the engine.  Were I to shift down at the ticks I'd get a real sudden and severe compression braking effect.  So, I wait until I know that downshift will be pretty smooth.  That's about 15 or 16 mph for shifting from First Range to Low, and around 30 for Second to First.

All in all, were you to watch me drive for any amount of time, you would probably describe my driving style as conservative and BORING!

Mike
Title: fuel consumption
Post by: Cobey on June 09, 2005, 01:56:10 AM
LOL.  No, mine is pretty boring - you at least use Low.  My downshift is a little different than yours though.  2nd to 1st needs to be ~20MPH or I get the braking effect.
Title: fuel consumption
Post by: Dennis Flora on July 29, 2005, 02:21:42 AM
If you shift into 3rd past 45 your beatin the hell out of it !!!  My autostick Trike weighs 1080 lbs and gets about 26-28 in town and 30-32 highway. If your jetted properly, you should be able to get the same or at least close. I always take off in 2nd, so I can't say what the speed for a normal shift into 2nd would be, but im gunna take a guess and say 20-25 mph... I hear some outragous shifting speeds on this site !!!  Id say shift into 3rd no later than 45, and duplicate the same rpm's for the 1-2 shift. And I say 45 if your driving it sorta hard too, 35-40 is easy is more normal driving.
These are Volkswagons, not Porsches... LOL  Don't beat em....
Title: Proper shifting...
Post by: Dennis Flora on July 29, 2005, 02:26:53 AM
And I don't mean cruising at 40 in 2nd gear either. You can putt along on level ground in 3rd gear at 30-35 mph and not be lugging the engine., just don't do it up a hill !!!  And if you have to accellerate, roll it on, don't slam it unless you drop it down to 2nd first. Be nice to your Volkswagon, it loves you....
Title: fuel consumption
Post by: Cobey on July 31, 2005, 03:10:20 AM
Sorry to be a pain in the butt, but, driving in Range 1 (2nd) is ok up to 55 according to the original owners manual.  Range 2 (3rd) can go from 0 to top speed, though the acceleration is poor.  Low range (1st) can be used from 0-35.  

You will of course use more fuel if you wind 2nd out to 55 all the time.  According to the manual,  you will get better fuel economy if you drop into 3rd at 20-25 mph.
Title: 55 in 2nd gear...
Post by: Dennis Flora on July 31, 2005, 03:33:45 AM
Number 1, it's just a 3 speed transmission. 2nd, if you go 55 in 2nd gear, thats nuts !!!  Every now and then, I make the 2-3 shift at 50 mph, but thats gotta be over 5000 rpm by the sound of it. I don't do it too often... You guys out here have entirely the wrong idea about these transmissions. You can call it what you want, but there just 3 speed manual transmissions, and you guys are revin the piss out of your engines. I bet my valves would float before I hit 55 mph in 2nd gear. You must be talkin the metric killometer scale or something. With 15 inch wheels and  165/80R/15 tires, a normal 2-3 shift is around 40 to 45. Shifting into 3rd gear at 50 is what I would do in a drag race, or to avoid gettin run over by a truck. You guys drive your cars the way you want, and call a 3 speed transmission an automatic if you want. Im am not coming back to this site and hear all this nonsense any more. Remember me when your cruising at 55 miles per hour in 2nd gear, when ya ought to be in 3rd, and you blow up you engine. I can't take this anymore... Whew !!!
Title: fuel consumption
Post by: Cobey on July 31, 2005, 03:42:55 AM
Dennis, there is no need for you to get all offended and pissy.  I simply quoted from the manual, which came with my Bug from VW.  If you want me to scan it so you can see for yourself, let me know.  We can all have a difference of opinion and still get along, exchanging ideas.  I take very good care of all 3 of my VWs, and never beat on them.

You're correct, the RPMs are up there if you wind 2nd out to 55.  So far, I'm the only one who said they do, but only when getting on the freeway.  I think your estimate of over 5000 is too high though.  I'll see if I can get a tach hooked up and let you know how it goes.

You are also correct that the tranny is 3spd manual trans with some added bits to function as a clutch.  No arguement there.  The only arguement here is how you feel it should be driven vs. how the manual says it can be driven.  That's it.
Title: Ouote from a factory trained mechanic at Niello VW.
Post by: Dennis Flora on July 31, 2005, 04:08:36 AM
He told me that Volkswagon made a terrible mistake calling the 3 gears of the Autostick "Drive Ranges", and most of the Autosticks sold were abused by their owners following the driving instructions in the owner manual. Because of this, they got a bad reputation for always breaking down, when in reality, they are fine cars, but should be drivin like a normal 3 speed, other than the occasional 2nd gear take off, and that should be done gingerly. He told me that even with my light weight Trike (1080 lbs), I should never hit it hard from a dead stop in 2nd gear. He said it's very hard on the engine, and it creates way too much heat in the fluid and excessive pressure against the torque converter seal. He said when the Autosticks were popular, he probably replaced over 100 torque converter seals because of people taking off in 2nd and 3rd gear. Now, I will beleive a factory trained VW mechanic every time, and I have always drivin/ridin my autostick as a normal 3 speed just out of comon sense.
Title: fuel consumption
Post by: Cobey on July 31, 2005, 04:20:13 AM
That's good info.  My buddy runs all three in his Ghia because he likes the better acceleration from a dead stop.  I've tried it a few times, and agree.  I'll have try it out more and work it in to see how it goes.  The last thing I want to do is break her.  I've been stocking up, just in case though.

I'm still interested in the RPMs though.  I'll have to rig a tach in Suzie '72 (4spd Super) before someone buys here and compare the RPM ranges between her and Edel ('72 Autostick Super) and report back.  With the AS  community getting smaller every day, the more info we have the better.
Title: RPM
Post by: Dennis Flora on July 31, 2005, 04:55:12 AM
I have a hand held tach, but the wires are too short to reach where I could see it while riding, but I will say this.... You can take off in 2nd gear if you want to, but do it very lightly. Don't mash down on the pedal all at once, roll it on slowly and let the car get up to speed (about 25 mph) before you mash down hard, and then shift into 3rd at 50 max, and thats bein hard on it. 45 mph is a nice, (brisk driving) shift into 3rd gear. I don't know who exactly wrote the owners manual, but I would love to drive his car for a week that way. Who am i kidding.... I could'nt even do that to an enemies car. LOL  I am easy on all machinery.... I'd rather slap the dude that wrote it that way. LOL   Anyway, now you know the real reason the autostick had such a bad reputation in their day. Hell, if you push anything hard enough, it will fall over.... and the autostick did....
Title: fuel consumption
Post by: Cobey on July 31, 2005, 05:02:45 AM
Well, at least I am doing that part right.  I don't thump the accelerator in any of my dubbers.  Besides wanting to take it easy on them, they are classic cars and I like to let them stroll down the road as opposed to race.
Title: Driving Style
Post by: Dennis Flora on July 31, 2005, 05:20:49 AM
Yep !!!  Treat her like a lady and she will stay with you forever...  Beat her up and she will take all your money and eventually leave you. LOL
Title: fuel consumption
Post by: Cobey on August 05, 2005, 01:02:03 AM
Okay, so I have been trying to make sure I use first for take offs.  The tricky part is the 1st-2nd shift point.  I found that if I slowly shift, (take out of 1st, pause for about 1 second as the motor dies down, and then ease it into 2nd), I cn make a smooth transition from 20-30mph.  If I shift it quickly, (one fluid motion, engine revs barely dropping off), I get a thump instead.

What does this mean?  Do I need to make an adjustment to anything other than my shifting habits?  I do know the time delay between when I put her in gear and when I can feel the trans engage is very short.
Title: Waiting for the tach results...
Post by: Dennis Flora on August 06, 2005, 12:10:45 PM
Did you ever get a tach hooked up for the test ???  Dennis
Title: fuel consumption
Post by: beetleman74 on August 11, 2005, 02:48:17 AM
so yea when i shift from 1-2 it takes a while for it to catch is that bad like 2-3 seconds maybe id check the stuff on my tranny but i have no idea what im doing :x oh yea and im tottally posting in the wrong topic haha
Title: fuel consumption
Post by: NOVA Ghia Owner on August 11, 2005, 03:16:33 PM
If I remember correctly, the owner's manual for my Karmann Ghia AS shows about a 1 mpg difference (lower) between the AS model and the manual.  The manual is rated at about 26 and the AS at about 25.  I can get exact figures if anyone is interested.

Regarding the shift from low to 1 to 2, my AS shifts just like a 3 speed manual.  Start out in low, listen to the motor and shift at about 15 to 20 mph to 1.  Shift to 2 at 40 to 45.  I let off the gas between shifts and the car shifts smoothly just like a properly driven manual.  There is no delay on my car.

This is my first AS.  I was skeptical about buying it but really enjoy driving it.  It drives really nice!
Title: fuel consumption
Post by: bookwus on August 12, 2005, 04:48:22 PM
Hiya Cobey,

As I recall, the amount of time for an AutoStick to actually do the shifting process between ranges is something on the order of one tenth of a second.  Much faster than in a manual.

If you are getting a "thump" when you shift from Low Range to First, I would imagine that you are also getting a noticeable thump when you shift into First Range from Nuetral.  Are you?

If that is the case, you might want to try to soften out those shifts by adjusting the control valve adjusting screw.  This can have the effect of softening the shift (assuming that the control valve still works as designed - many do not) but it also lengthens the amount of time for that shift.

So, you are left with this sort of situation........you can fiddle around with the CV adjusting screw and then road test the car.  Try to find a happy medium between a good positive shift and a smooth shift.  As a matter of fact the "try it and test it, try it and test it again" method is just what the Bentley suggests.

Mike

1970 AS Bug
Title: fuel consumption
Post by: Cobey on August 16, 2005, 08:49:31 PM
Quote from: bookwus
If you are getting a "thump" when you shift from Low Range to First, I would imagine that you are also getting a noticeable thump when you shift into First Range from Nuetral.  Are you?


Yup.  There is a thump moving to any gear from neutral.  I always thought it was normal like in a full automatics.  This is a it bigger a bump though.

Quote from: bookwus
If that is the case, you might want to try to soften out those shifts by adjusting the control valve adjusting screw.  This can have the effect of softening the shift (assuming that the control valve still works as designed - many do not) but it also lengthens the amount of time for that shift.

So, you are left with this sort of situation........you can fiddle around with the CV adjusting screw and then road test the car.  Try to find a happy medium between a good positive shift and a smooth shift.  As a matter of fact the "try it and test it, try it and test it again" method is just what the Bentley suggests.

Mike
1970 AS Bug


Is this the adjustment you mean - http://www.volks.org/vwar/tecnical/adj_speed_engagement.php

I was just looking at that.  In mine, the gear engages almost instantly.  There is zero time delay between when I move the selector to the new gear and when it engages.  I don't think I even have to take my hand off the selector, but I'll have to check on the trip home to be sure.
Title: fuel consumption
Post by: Cobey on September 18, 2005, 11:49:55 PM
Well now, I finally had a moment to give the adjustment a try.  Gave it just about half a turn total and she shifts VERY smoothly now.  I will see what happens if I back it off a little, but after a 15 minutes trip with lots of stops and shifts, it seems a whole lot better.  :)