Fuel Economy Tips

Ric Woodruff

BANNED, Ric went to Coventry.
Joined
Feb 19, 1999


How you drive:

How you drive is biggest factor affecting fuel consumption. Driving harshly, that is, accelerating and stopping hard, is the easiest thing to change. Not only does it adversely effect your mileage, but it puts you in a very high risk group. Moving you from point A to point B is about physics, it takes energy (gas) to accelerate and stop you (because you must reaccelerate to proceed again). Ever notice big rigs in the city, they pace the lights. Why do you think that is? We make a big thing about 'hitting all the lights', imagine pacing the lights so that you almost always hit them. That will have a dramatic effect on fuel economy. Lets face it, saving 25 cents on a tank of gas won't pad your retirement fund, but getting an extra 50 - 100 miles out of a tank of gas will.

Where you drive:

Its no secret that your vehicle gets better mileage on the highway than in the city. This is directly related to starting and stopping. If you can, plan your route to take advantage of the highway.

When you drive:

If starting and stopping are fuel mileage killers and you can't take advantage of choosing your route then consider when you drive. It doesn't take a rocket scientist to realize that driving in rush hour is the absolute worst time. Consider this, when your sitting at a red light, your getting 0 mpg. Seasons and weather also have an effect on consumption. Driving in rain or snow is a mileage killer. Especially snow, if you can avoid it, do it.

Engine Tune:

Common sense here. An out of tune engine can play havoc with consumption. A sticky choke, an intermittent misfire are all relatively inexpensive to correct with a very good return on investment.

Wheel Alignment

Are your roads bad, if their like they are just about everywhere else you most likely need a wheel alignment. Imagine having one of your wheels locked and skidding for 50 feet for each mile you drive. What would that do to your fuel consumption? Right.

Brakes

A dragging brake or maladjusted parking brake is not just dangerous but costly as well.

Tire Pressure & Type

Snow tires or under inflated tires are both easy and cheap to correct. Studies have been done that show almost 70% of the vehicles on the road have under inflated tires.

Options

Ask anybody with air conditioning in their vehicle what it does to fuel mileage. The same goes for optional equipment that places a heavy load on the electrical system. It takes extra energy to drive your alternator to generate that electricity, more than you think.

Vehicle Accessories

Roof or luggage racks, bug deflectors, running boards all have negative affect on mileage, Sport utility vehicles are popular now, does yours have a little air deflector to keep the rear window clean? Same thing for pick-up trucks, if you have nothing in your bed and are going on a long road trip, open your tailgate. Thats worth almost 2mpg all by itself! A better solution is a tonneau cover and leave the tailgate up!




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Ric Woodruff

Braumeister von Sehr Gutem Bier
Since the Last Millennium

1998 Jetta TDI Sport
 

Alek

Veteran Member
Joined
Apr 12, 2000
Location
Ljubljana, Slovenia
Ric:

On the 27th June 2000 I sent you an E-mail on the rwoodruff@webinbox.com address. Today I was notified that delivery was unsuccessful.
Sorry for that.
Anyhow I can't help you with ALP. Your posting was first time I heard of it.
We'll have to communicate through forum.


Best regards,
Ales K.
 
S

SkyPup

Guest
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Ric Woodruff:


How you drive:

How you drive is biggest factor affecting fuel consumption. Driving harshly, that is, accelerating and stopping hard, is the easiest thing to change. Not only does it adversely effect your mileage, but it puts you in a very high risk group. Moving you from point A to point B is about physics, it takes energy (gas) to accelerate and stop you (because you must reaccelerate to proceed again). Ever notice big rigs in the city, they pace the lights. Why do you think that is? We make a big thing about 'hitting all the lights', imagine pacing the lights so that you almost always hit them. That will have a dramatic effect on fuel economy. Lets face it, saving 25 cents on a tank of gas won't pad your retirement fund, but getting an extra 50 - 100 miles out of a tank of gas will.

Where you drive:

Its no secret that your vehicle gets better mileage on the highway than in the city. This is directly related to starting and stopping. If you can, plan your route to take advantage of the highway.

When you drive:

If starting and stopping are fuel mileage killers and you can't take advantage of choosing your route then consider when you drive. It doesn't take a rocket scientist to realize that driving in rush hour is the absolute worst time. Consider this, when your sitting at a red light, your getting 0 mpg. Seasons and weather also have an effect on consumption. Driving in rain or snow is a mileage killer. Especially snow, if you can avoid it, do it.

Engine Tune:

Common sense here. An out of tune engine can play havoc with consumption. A sticky choke, an intermittent misfire are all relatively inexpensive to correct with a very good return on investment.

Wheel Alignment

Are your roads bad, if their like they are just about everywhere else you most likely need a wheel alignment. Imagine having one of your wheels locked and skidding for 50 feet for each mile you drive. What would that do to your fuel consumption? Right.

Brakes

A dragging brake or maladjusted parking brake is not just dangerous but costly as well.

Tire Pressure & Type

Snow tires or under inflated tires are both easy and cheap to correct. Studies have been done that show almost 70% of the vehicles on the road have under inflated tires.

Options

Ask anybody with air conditioning in their vehicle what it does to fuel mileage. The same goes for optional equipment that places a heavy load on the electrical system. It takes extra energy to drive your alternator to generate that electricity, more than you think.

Vehicle Accessories

Roof or luggage racks, bug deflectors, running boards all have negative affect on mileage, Sport utility vehicles are popular now, does yours have a little air deflector to keep the rear window clean? Same thing for pick-up trucks, if you have nothing in your bed and are going on a long road trip, open your tailgate. Thats worth almost 2mpg all by itself! A better solution is a tonneau cover and leave the tailgate up!


Ric, Cut N' Paste? The least you could have done is change the word gas to diesel!


<HR></BLOCKQUOTE>
 

Ric Woodruff

BANNED, Ric went to Coventry.
Joined
Feb 19, 1999
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by SkyPup:
<HR></BLOCKQUOTE>

It is generic information that applies to both gas AND diesel vehicles.
 

ENUTPEN8

Veteran Member
Joined
Jul 31, 1999
Location
AR , USA
Gas? Choke? Snow tires? Alignment? I don't think the .50 cal. creates that much drag... Is this cosmic?? Hey, Ric, you weren't driving the '54 DeSoto in the Mobil Economy Run that year, were you?? Driveon...NickatNight

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1999 green/tan MkIV Golf GLS TDI auto/lux, flaps down, K&N, Bilstein HD.
 

MacGyver

Veteran Member
Joined
Mar 13, 2000
Location
SW Ont, Canada
TDI
1997 Jetta, black
The alternator eats 1hp to make about 22amps. I'm not going to look it up, but I remember the manual telling how much more fuel it takes to leave the rear defroster on continuously. Makes sense.
 

Ric Woodruff

BANNED, Ric went to Coventry.
Joined
Feb 19, 1999
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by MacGyver:
The alternator eats 1hp to make about 22amps. I'm not going to look it up, but I remember the manual telling how much more fuel it takes to leave the rear defroster on continuously. Makes sense.
<HR></BLOCKQUOTE>

Wow, that is a really inefficient alternator if true! 22 amps x say, 14 volts = 308 watts. 1 HP = 746 watts, so the alternator is only 41% efficient??? Doubtful.
 

fnj2

Veteran Member
Joined
Aug 1, 1999
Location
Wellfleet, Massachusetts, USA
I don't find the figure doubtful at all - first of all, the 1 hp figure is obviously approximate, and next and more importantly, 22 amps is only a small part load; the alternator is operating well below max efficiency.

Keep in mind also the alternator must operate over a wide rpm range, and cannot deliver max efficiency over the entire range - most likely it is best at high rpm.

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Mutter at idle, growl at full throttle
 

cars wanted

Veteran Member
Joined
Jul 30, 1999
Location
Rockville, Maryland U.S.A.
TDI
Golf GLS-TDI, 2000, white/beige
Although I expect an alternator's AC generator to be quite efficient, I think that the rectifier diodes, (to make it DC voltage), would take a hit in maximum efficiency.
 

MacGyver

Veteran Member
Joined
Mar 13, 2000
Location
SW Ont, Canada
TDI
1997 Jetta, black
That was an indirect quote from some car magazine I remember reading years ago.

Ric, how efficient do you expect it to be? It is afterall a mechanical device. I work with 48V telephone equipment. The modern charging equipment is 80-90 percent efficient, and it is all electronic, solid state. No moving parts. Remember the last time you touched a running alternator? Not freezing cold was it? Where do you think all that heat energy came from? Belt, pulley, bearings, magnetism, rectifier...I think 40 percent is respectable.
 

Powder Hound

Top Post Dawg
Joined
Oct 25, 1999
Location
Under a Bridge, Crestview, FL, USA
TDI
'00 Golf 4dr White 5sp, '02 Jettachero 5sp, Wife's '03 NB Platinum Gray auto(!)
MacGuyver,

Don't worry about Ric's pronouncements on anything. He doesn't know what he's talking about.

------------------
Always interested in steep & deep.
Ski resorts closed! Break out the cameras and fly rod ...
 

SpeedingAgain!

Active member
Joined
Apr 1, 2000
Location
Ardfern, Argyll, Scotland
TDI
none
All this business about keeping the revs down and not accelerating harshly may be good for the fuel consumption.
However, it is not good for the cylinder bores, rings and ring grooves for the engine to be run on a low load all the time. Running a diesel engine on low load continually allows build up of carbon. This is exaggerated with our TDI engines with the egr valve.
You may already know this but carbon polishes the liners leading to drop in compression, it also sticks in the ring grooves eventually jamming the rings and a sticking ring will wear badly on the ring grooves on the piston and on the liner, resulting in even less compression still.
The only way to fix it is to strip it down.
Or you could simply give the engine a bit of welly every so often which will burn all the carbon off! That's my excuse any way.
 

jayb79

Top Post Dawg
Joined
May 20, 2000
Location
Exeter,NH
After putting around for a couple of hours mash the pedal and let the revs come up to about 3000-3500 in a couple of gears and watch the black cloud come out the back. Poof all cleaned out.
 

Ric Woodruff

BANNED, Ric went to Coventry.
Joined
Feb 19, 1999
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by jayb79:
After putting around for a couple of hours mash the pedal and let the revs come up to about 3000-3500 in a couple of gears and watch the black cloud come out the back. Poof all cleaned out.
<HR></BLOCKQUOTE>

The black smoke is a result of build up of soot in the exhaust system, and has nothing to do with "cleaning the engine". The surface areas of the exhaust manifold, the exhaust pipe, the muffler and catalytic converter are very extensive.

If you feel better blowing out all that soot, go right ahead (I do it myself occasionally), but don't expect your engine to run any better afterwards.

The term "Italian tuneup" came from Italian sports cars that ran cold under normal driving and consequently had fouling of spark plugs. Reving high and driving hard tended to clean them, and made the engines run better. We have no spark plugs, so reving high and running hard does nothing to a diesel engine.


Ric
 
S

SkyPup

Guest
Rics fallices notwithstanding, the TDI oxidizing catalytic convertor does not oxidize soot until it reaches and holds a temperature of 300 degrees F, which normally is a few minutes after startup, therefore the soot DOES NOT build up in the exhaust system as Ric imagines as long as the car is driven and not idled for extended periods of time.
SpeedingAgain is exactly right about the carbon build-up in the cylinder, this is why Ric's ride is burning so much oil and smoking, it the oil he's burning from the way he drives, not the soot!
 
S

SkyPup

Guest
I don't use the crummy low cetane high sulphur fuel like you do. For me to come anything close to what you describe as your sooted tailpipe, I'd have to leave a slice of toast in the toaster too long and then scrape off the carbon with a knife before buttering it up!

Soot oxidizes over 300 F., your ceramic platinum element that causes this catalytic reaction is probably killed from your high sulphur low quality fuel diet!
 

Ric Woodruff

BANNED, Ric went to Coventry.
Joined
Feb 19, 1999
SkyPup: Scrape the inside of your tailpipe with your thumbnail - you'll see EXACTLY what I mean.
 

Ric Woodruff

BANNED, Ric went to Coventry.
Joined
Feb 19, 1999
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by SkyPup:
I don't use the crummy low cetane high sulphur fuel like you do. For me to come anything close to what you describe as your sooted tailpipe, I'd have to leave a slice of toast in the toaster too long and then scrape off the carbon with a knife before buttering it up!

Soot oxidizes over 300 F., your ceramic platinum element that causes this catalytic reaction is probably killed from your high sulphur low quality fuel diet!
<HR></BLOCKQUOTE>

I'll examine your tailpipe personally at Carolina Beach!
 
S

SkyPup

Guest
Ric, both the tail pipes on my two TDIs are not the small ratty OEM chokers like you are used to, instead they are the huge Techtonics Tuning T-304 Stainless Steel units with the straight through Borla Stainless mufflers, even the hanging clamps are stainless.
--------------------------------------------
The Question is then, Are You MAN Enough to Handle These Huge AfterMarket Pipes?
---------------------------------------------
I seriously doubt it!
 

Ric Woodruff

BANNED, Ric went to Coventry.
Joined
Feb 19, 1999
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by SkyPup:

The Question is then, Are You MAN Enough to Handle These Huge AfterMarket Pipes?

<HR></BLOCKQUOTE>

It depends upon what your definition of "handle" is.
LOL!
 

Heinrich D W

Member
Joined
May 1, 2008
Location
Linwood,ON Canada
TDI
VW Jetta 2003 & 2001
Heinrich D W

I have question concerning fuel economy and I have not seen anything that answers my question. My 2000 TDI idles rough and I think it could do a little better on fuel, does anyone know whether injector nozzles make a diffirence and if I replace the nozzles with the BOSIO 442/706 do I have to get them recalibrated? My TDI has almost 500,000 km on it.
 

Dieselducky

Veteran Member
Joined
Oct 13, 2011
Location
Dunnville
TDI
88 Jetta Diesel - 2000 Jetta TDI - 04 BMW M3 - 06 Kia Rio - F350 Superduty - 87 Buick GNX - Mobile Cranes
I have question concerning fuel economy and I have not seen anything that answers my question. My 2000 TDI idles rough and I think it could do a little better on fuel, does anyone know whether injector nozzles make a diffirence and if I replace the nozzles with the BOSIO 442/706 do I have to get them recalibrated? My TDI has almost 500,000 km on it.
This thread is over 10 years old btw....Go get a Diesel purge performed on the car before you start changing parts.
 
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