Fuel Mileage Problems

Capt. Mike

This topic was created to consolidate several fuel mileage questions. Please post all mileage questions here. -- Capt. Mike

Capt. Mike

Transferred from an original topic titled "Gas milage" posted by Dean, Junior Member, 05-18-2000 07:34 AM

I have a 75 camper 1800cc FI and want to know if driving 3 hours straight at 100kms using 3/4 of a tank is usual?

kh, Junior Member, 05-19-2000 10:35 AM

If a train leaves Baltimore at 3:00 local time and averages....ummm...sorry

I've averaged 18mpg on a 1900cc FI Camper...this is combination city/highway, YMMV.


Capt. Mike, Moderator, 05-24-2000 09:51 AM

/infopop/emoticons/icon_redface.gif Mileage is subject to many variables and must be tracked over a considerable period of time to be a valid estimate. Several tanks, not just one, or a partial read via the gauge.

My numbers are US gallons -- landlubber miles, so you'll have to do the metric conversion, but VW's official EPA estimate was 17 mpg. Yet my '79 averaged 19.25 on all of its trips. Most of these were heavily loaded -- max GVWR -- camping trips including considerable mountain driving. Low over the 10 years was 18.18; high 20.88. I found 17 around town common and empty highway 19-21. I've had individual tanks go below 15 (strong headwinds) or over 24 (probably didn't get a full tank), but those are exceptions.

But I also drive easy and kept mine well maintained and tuned up. Typically I shift at 3,500 rpm and cruise at 3,000 (55 mph). VW aerodynamics and engine power curves are such that mileage drops off rapidly above that.

Numbers on my '90 Vanagon Westy 4x4 are similar even though the vehicle is heavier and EPA is down to 16 mpg. With it, my average is 19.60 mpg with a low trip of 17.71 and high of 20.38 mpg. That includes fuel taken from the tanks for Coleman dual-fuel stove & lantern so actual numbers would have been slightly higher.
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Capt. Mike

Transferred from a post titled "Bus jerks/ poor mpg" by davidm, Junior Member posted 06-18-2000 02:06 PM

Hello Friends, I have a 76 westy and here's the problem: I have no idea if these two problems are related but...

My bus is tuned regularly. (clean oil, adj valves, points, timing, etc) I used to get around 16-19mpg on highways. Now I only get around 10-12. Also, only on long trips, my bus will occationally jerk, sort of like the gas is getting cut but more of a jerking motion. It'll do this occationally, sometimes worse than others and it has even died completely a couple of times. It seems to act up more when I'm going around 45-55 in 4th or when I go up hills, though it's not limited to this range. Once when it did die I noticed the white wire from the coil to somewhere in FI computer box had a poor conection at the coil. I fixed the connection and the bus started... hooray the problem fixed... WRONG! Next big trip, same problem, this time not until about 150 miles into driving. After the last trip when we pulled into town I noticed the idle was a bit sparatic, but the engine seemed to sound fine. I replaced to head temp sensor to no avail and I'm in desperate need a help! I travell with my four year old and no one wants to break down with a toddler in the car. Thanks for your help.

Capt. Mike, Moderator, 06-19-2000 08:43 AM

There is a fuel injection troubleshooting chart posted on my pics page linked from this site's main page. Look in the technical diagrams folder. It will check the FI system out with a common volt-ohmeter.

Your symptoms are consistent with an erratic air-flow meter. It operates on resistance with info fed from the FI brain. Erratic signal will cause it to flutter or the inner coil could be burned in one spot and misbehave at a particular RPM/load combination.

Obviously, any corroded or bad connections to the brain box could drastically effect running. Try jumping or replacing that white wire that feeds RPM to the FI brain to make sure it's not still the source of your problem.

This can cause poor mileage, though I wouldn't rule out a stuck cold-start valve.

Capt. Mike

Transferred from a thread titled "MISERABLE fuel economy" posted by TomTerrific, Junior Member posted 07-29-2000 10:15 PM

Have '73 Westy w/Auto. Getting about 6 mpg @ 55 mph after: carb kit rebuild, new 009 dist, valve adjust, elect. fuel pump, pertronics elect ignition. Have also removed all (?) hardware related to emissions control after AIR seized on trip. Runs smooth at 12 deg btdc, 58 deg dwell. Chokes not sticking. Starts nicely w/no throttle req'd. I'm out of ideas.

Capt. Mike, Moderator, 07-30-2000 09:00 PM

To start with, your timing is supposed to be 5° AFTER TDC (see Bentley Section 5-19.2, table I. Dwell is 42-58° used points; try to get it back into the middle of the range.
IP: Logged

CGOTTS, Member, 07-31-2000 01:10 AM

First off, did you decide that you don't want to use a mechanical fuel pump any more? Or the electric one easier to get to and put into the system? Reason I ask that question is due to the fact that an electric one can - depending on which brand & model you purchased - put to much fuel into the carbs. This is a common problem with electric fuel pumps, thus the fuel pressure regulator installation. From the sounds of things - you are still running the stock solex carbs? Or did you go to a single progressive type carb? On my '74, someone had installed a fuel injection motor, which doesn't have a spot for a mechanical fuel pump, and so I can relate to your problems. One fuel pump, the small square cube type, did not work well, due to its low fuel pressure output for dual carbs. Once I realized what the problem was, I purchased a carter high pressure type, one with more fuel pressure & flow, and that solved that problem. But then the fuel mileage - I installed a fuel pressure regulator, and after trying a couple of different settings, found one to work well, and it improved my mileage as well. Keep in mind, the stock distributor your engine came with is a pretty good unit as well - the #205 Bosch distributor is basically an 009 distributor with vacuum assist - try putting this distributor back on and see if things change when put back to the correct timing settings. Let me know what you come up with. Hope this helps. CGOTTS

pbeitz, Junior Member, 08-02-2000 09:53 PM

My 73 westy camper is also getting poor mileage at about 13 miles per gallon in mixed
freeway and city driving. I was told when I bought it (by a mechanic and previous owner) that I should get close to 20 in the city. Clearly this is not happening. She's just had a full tune-up and has new tires on her. She has a relatively new engine(15k miles) and new carbs. I always use premium gas, 92 octane. She's got relatively new KYB shocks up front. Is it unreasonable to expect 20 MPG or should I be doing anything else to up the miles? Sorry I keep posting in the wrong place. I'm just learning how to use message boards. Hope I did it right this time. Any kind of help or advice would be greatly appreciated. Thanks!!!!

Capt. Mike, Moderator, 08-13-2000 08:56 PM

EPA was 17, so 16-17 city is common enough. Good highway is 19-20. Bus mileage is VERY dependent upon driving style. High revs for shifting and high speed will kill the mileage quick. Try shifting at 3,500 RPM and cruising at 3,000 (55 mph) for a few tank fulls and see if it stablizes at the above numbers. Freeway speeds of 65 & 70 mph will kill the mileage in a hearbeat -- let's face it, it's as aerodynamic as a breadbox.

See the Gas Octane post on the TIPS board; you're wasting money on 92 octane and it may actually hurt your mileage.

Did you get the right size & rating of tires? See the WHEEL & BRAKES forum posts on tire profile & on OE/OEM tires.


New member
I’ve seen a product called “Magnetic Fuel Saver” (brand name: Fuel Boss) advertised in a parts catalog (JC Whitney--I'm not endorsing them —shipping rates are too high) and I wanted to get some comments/feedback.

The product is a magnet that snaps around the vehicleÂ’s fuel line and is suppose to break up any ‘hydrocarbon clusters’ in the fuel which in turn exposes the fuel to oxygen for more complete combustion.

The ad claims “After performing the HFET fuel economy per 40 CFR 600.113-88 EPA accepted Test...we see a significant decrease in hydrocarbon, carbon monoxide and oxides of Nitrogen, and an 11.6% increase in fuel economy after installing the Fuel Saver on the test vehicle." Liphardt & Associates, Inc.

I’m not a chemist or physicist, but I am a skeptic. Is this just snake-oil? Any thoughts or experience with this product?? I've checked the posts and the archives and didn't find any mention of this product. Thanks

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Capt. Mike

You've got a right to be skeptic. It's as phony as a Slick Willie Clinton dollar bill.

I had always poo-poo'ed anything that was sold with "testimonials". If it was any good, they would have corporate backing and professional lab results to back it.

Cummins, the diesel company, approved the most respected of the bunch, Sumag. It had lab results to back it up. MUCH later, I found the lab was some fly-by-night Hong Kong lab, not a certifed US or European. Anyway, with a 110% money back guarantee from Cummings, I bit. /infopop/emoticons/icon_redface.gif

I took it on as a project, keeping records that exceeded the warranty requirements and for a full year. Result? IT DON'T WORK!

Here's my results in my Redneck pickemup truck:

Pre installation mileage: 15.31 w/ trailer, 19.07 empty.

Break-in (they tell you it takes 2,000 miles to begin working. Did you hear the alarm bells?): 18.82 empty.

After installation & break-in: 14.47 w/ trailer, 18.51 empty. That's over 22,000 miles!

Do you see where this is going? It didn't do a damn thing for mileage. I'm not ready to blame the drop on them -- loaded trailer mileage varies tremendously and I might have had more in-town empty mileage than the base period. But it sure as hell didn't get anywhere close to the promised gain. It took me about a year to get the warranty claim refund! And that was from Cummins -- Sumag had long since disappeared into the woodwork.

:p So to answer your question, it's not snake oil -- it's snake venom. Stop & think. Every US manufacturer is spending millions to get a 1/100th % MPG because of the government CAFE regulations and resultant fines. If a $5 (manufacturing cost) magnet would do 5%, you'd find one the size of a football on every new car.

Spend your money on a tune-up.
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New member
I drive an automatic 87 Westy. I've only had it for a short while. Yes, it has cheap tires that need replacing (too soft)

Q: What kind of mileage do automatic drivers seem to be getting? I commute in this car 50% highway and 50% side roads (not very stop and go, pretty decent commute). I seem to be lucky if I get 16 MPG, I'd say its usually worse.

When I first got it we went on a trip where the driving wasn't any better than my commute and we seemed to get between 17 and 20+. I wonder if something has changed...

Any tips would be appreciated.

Capt. Mike

As I remember, the EPA numbers for an A/T were always 1 mpg less than the equivelent manual trannies. Although the EPA test generally delivered lower mileages than actual, it seems to be relatively accurate in the variation.

One problem A/T owners face is that they have one less gear and tend to drive a lot harder to make up for the loss of performance, so they take a double hit on mileage.

Check the thread under engines about breaking in a new or reman engine and note the driving tips there. See if your driving follows the "easy driving" level and what kind of mileage that will give you so you have a comparison to those of us that are pulling 19-20.


New member
Good day my friend, (87 Westy, 4 speed)
I did 330 KM today(205 mile) with a full thank,(Canadien fuel/ lower quality!!! believe me)90% highway, i am a bit confuse with our liter vs US Gallon and KM/mile but i think my West is doing about 16/17 MPG.
I paid $.78 a liter and put $37.00 CAD in it.
I am not shure about the US gallon VS liter.

Just so you know, my Honda Civic is doing 600 km with a full USA thank (in Maine and Mass.)
and i do about 475 km in Canada????
Regards, Ben

Capt. Mike

A liter is .2642 US gallons, or 3.79 liters per US gallon.

A kilometers is .6214 statute miles.

An Imperial Gallon (old Canadian measure but still found or heard) was 1.25 US gallons.

Typically, US owners use miles per gallon for mileage, but Canadians often use the metric standard of liters per 100 km.


New member
Follow up to my post:

For a couple of tanks now I've really been taking it easy. I was already very light footed around town but I did cruise at about 70 on the highway. Now I'm a gentle giant in the city and cruise around 62 on the highway... it's made no difference!

I guess the question is, am I getting piss-poor mileage or am I getting expected mileage. I consistently get 15/16 MPG with a 50/50 mix of city and highway driving.


Capt. Mike

I think you'll find the EPA was 17 city; 18 higway.

An A/T has a (Drive) high gear of 1.00:1 PLUS the slippage of the torque converter. That's ~15% worse than a M/T's 4th (0.85:1) Add the acceleration inefficiencies and it's not surprising an A/T would get worse mileage.

I know you call it 'gentle', but 62 (true) on a M/T is ~3,500 RPM, so I'd guess it's pushing 4,000 on an A/T. That's pretty deep into the "Decling Rate of Return" per my old econ prof. You got a tach? Work your foot to shift at 3,500 and cruise at 3,000. See if that doesn't get you back up around that EPA set of numbers.

I'm not saying you don't have a engine or transmission problem, but you haven't mentioned any symptoms to indicate one. Black smoke; fouled plugs, surging &/or missing . . . or the things you've checked and can be eliminated like tune ups and shop diagnosis of the FI electronics.

Sorry, but for mileage alone to establish a problem, it has to be referenced to the same plane (driving habits, terrain & load) the others are getting. I really don't hear much input on A/T mileage; I've only known one or two that had them and the subject never came up. Hopefully some of the other readers with A/T can give you some MPG numbers that are correlated to RPM & load patterns. I'd like to see some myself as my only reference is to my few times having to kick up the speed to meet some time constraint, and a couple of owners I know that consistently push the RPMs above that 3,000-3,500 bracket. In both those scenairos, mileage goes to H in a steep dive.

PS: Did you get rid of those junk tires? They DO make a noticeable difference.
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New member
Thanks for the feedback.

I have kept my eye on the tach and honestly don't really climb beyond 3500 usually but I'll keep an eye on it.

Tune-up wise, I've got a good mechanic (he's the next one I'm asking about mileage) and I've had a complete tune-up recently as well as emissions tests.

Tires, nah, they still suck and I'm hoping they're part of the problem. Just got tire money for my birthday though and, as I've seen only positive feedback, I'm off to Costco for 5 new ones. I'm going to follow your 5 tire rotation plan...

Surging, yeah, I've got a little of the "vanagon syndrome" going sometimes. I'm waiting for the $130 to come through on that though... it doesn't happen that often and hasn't been a huge inconvenience yet - knock on wood.

Thanks again - I'd appreciate notes from anyone driving a 2.1 AT.


Capt. Mike

Fuel Milage

Ken, Junior Member, 05-02-2001 06:24 PM

I am the owner of a 1988 Automatic Westfalia with 166000 Km on the odometer. I have Michelin 185 R 14 94R tires which have the reinforced sidewalls.I average about 20 to 22 Mpg (Canadian Gallon). I agree with Capt Mike that wieght carried and speed are factors that greatly affect your gas milage. The 20 to 22 Mpg translates to 16 to 17 Mpg to an American gallon.I am not an agressive driver an this mileage has been consistant since I have had this van. The automatic turns at 3650RPM at 100Kph/62Mph-3400RPM at 90Kph/55.8Mph-3000RPM at 80Kph/49.6Mph. The fuel milage for me is not an issue when I do not have a large bill for accomadation at the end of the journey.



OK...I'm an "old school" stock dual-port 1600cc pilot, and i am interested in hearing what kind of mileage all of you others are getting or expect to get in the 68-71 Westys? Mine has been just over 16mpg for the past few tanks, and I have been taking the "drive 55mph or less" on the highway advice. Only a few times have I caught myself creeping up toward 60mph. My shifting has been in the 3000-3500 range consistantly. I'd really be interested in hearing what I should expect. I know the manual says "22.6mpg" for the standard bus, so I would expect that maybe an unloaded Westy should be in the 18-19mpg range?
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Capt. Mike

I'm a slow believer in what I hear at gatherings because lying about fuel mileage seems to go along with lying about the size of the fish that got away. When I was checking out diesel pickups for a tow vehicle, I had owners tell me they were getting high 20's towing 18,000 lb. 35' RV's. And always uphill and through the mountains. Yeah, right!

I've also heard some fairy tale level ones at bus gatherings. I think I'll stick to the ones that indicate with the easy driving breaking into the lowest 20's is possible. I'd suspect dropping into the mid-teens indicates a problem.

Section 3-5.1, table b-11 gives the most common causes of drop. Float, needle valve wear and CO adjustment are the most common as a carb ages out. I advise people adjust carburators the same as FI -- with a CO meter. The old "rolling idle" and by ear are pretty lousy compared to reading the numbers off a dial! Try for about 3% +/- 1%.


New member
Just got back from a trip to Deadhorse, Alaska.

The mud was SO bad on the Dalton Highway it tore the wire from the oxygen sensor.

I saw the mileage drop from an average 17.8(high of 20.5, low of 15.5) but went right back to the high side with a replacement sensor installed.

Thanks to the website for the clues to what that funny thing was sticking out my exhaust pipes!


New member
Hi all,

I drive an "84 Vanagon soon to be Westy. I had the conversion to the Jetta/Golf A3 2 litre engine done a couple of years ago, I average 10.3 litres/100 km (22.8 mpg US). Lots of power/no more head problems.


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Capt. Mike

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New member
Greetings all,
Ive taken a look at the other messages in this section to obtain an idea of what the normal consumption appears to be like for westys.
It makes me feel a little better but I am still guzzling fuel.
My 81 air cooled Vanagon recently had a 1750cc Transporter engine installed. We kept the original fuel injection from the old 1900cc (this was a lot of trouble but I thought would pay in the long run).
On the highway I am averaging 14mpg....this is with low rev driving and smooth gradual acceleration, a load of two people (driver included) with circa 60kg weight of accessories.
Now I would accept this consumption as poor-ok, were it not for the following concerns.
1. I am uncertain if Im using the correct fuel types as I cross Europe. In Norway I was using a 98oktane(with lead).
Most other countries have only lead free, so initially I was using 98 lead free with a lead additive. I have since dropped to a 95 lead free with additive after reading the posting in "tips".
2. Since the first fuel change in Denmark , I was experiencing a surging and occasional stalling on the highway. It was likely to be many things, but after a general service in Hamburg by a Westy man (new plugs, filters, oils change and a CO adjustment to 2%), the bucking/stalling dissapeared but fuel consumption just as bad.
The only symptom left is this incredible difficulty in starting cold......it is as though all sparks are present but the fuel just seems too "damp" to fire, which is why I still suspect an incorrect fuel type.
I have to pump[ much fuel in the starting process, and no, it is not flooding.(strange).
Overall Im enjoying the westy experience and continue to feed the machine at every 250km or so, but if anyone has a tip or suggestion that may save me a little Id be happy to hear it (my own tip is to ferry from Croatia to Greece to avoid the road miles!).
PS I also wonder if what Capt Mike has mentioned about an electric fuel pump fitted over a carby is not an issue...this 1750cc engine was with mechanical fuel pump.