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Sun Aug 24, 2008 7:34 am

Hiya, folks.

I keep a mileage log for each of my vehicles. I calculate mileage on how much I've had to put in to fill the tank (no partial fill-ups) and the mileage since the last trip to the pumps. It ain't nuclear physics, but I reckon my system works well enough to give me a general idea regarding my mileage.

My 86 Caprice wagon (a great behemoth of a car, and my winter ride) pulls 22 or so MPG.

Our beloved Sophia (85 Weekender) used to average c. 12.5 mpg before this summer's GoWesty engine swap. Now, with the 2.3l replacement, we're down to 11.5 mpg or so. This is with skinny hard little Korean tires at 60 PSI, all highway, constant speed, and revving somewhere around 3400 RPM/60 MPH.

This means my four cylinder van (albiet a great heavy lump of teutonic overengineering, with the aerodynamics of a 1960's era John Deere combine, thrusting through the atmosphere via the efforts of the Hardest Working Four Cylinder Engine in Show Business) gets half the mileage of Miss America, my monstrous wagon of doom, running a 305 with a 4 bbl carb.

Does this sound right to you? Is there something wrong with my calculations?

Dan

Sun Aug 24, 2008 8:02 am

I don't think that your way of calulating is a problem. However, if you research the forum - most folks get better MPG than you are getting. You should get high teens to low 20's in the best case.

I would start reading the forum to find out what can help. I am not sure what things you changed at the time of your engine upgrade but some things to look at are, Oxygen sensor, Temp sensor, exhaust cat (plugged) etc etc.

Sun Aug 24, 2008 8:15 am

Your asking an engine with half or less horses to push around the same weight as the Chevy, plus having the benifit of a 4x8 sheet of plywood on the nose of it--
The Vanagon is as aerodynamic as a 53 ft. Fruehauf semi trailer.

I'd have to say you've got some engine management problems, you'll have to be checking out.

Sun Aug 24, 2008 8:31 am

> Is there something wrong with my calculations?

Maybe the distance traveled is not accurate?

I would start by comparing your odometer accuracy, against a GPS.

speedos and tachometers in vanagons are notoriously innacurate.

I had a tach in one van that was off by 800rpm. In another van my speedo is off by 5mph. I dont think you can trust your tach, speedo, or odometer, unless you confirm they are accurate.

based on your reported gas mileage before and after the conversion, my bet is your odometer has been lying to you all along.. most vanagons get over 15mpgallon..

Jon

Sun Aug 24, 2008 9:48 am

Jon_slider wrote: Maybe the distance traveled is not accurate?

Good thinking, mate, but our pilgrimage to GoWesty included a rebuild of the instrument cluster - the old tach read stupid high (now fixed) and the speedo was indeed off, reading c. 5mph slow compared to GPS. These issues have been resolved, thank God. Since this work, we've put c. 2000 miles on 'er.

So what exactly should we be checking?
- The O2 sensor
- Temp sensor
- Cat (although she seems to flow OK - decent puffs against my leg when I walked by yesterday)

What else?

Sun Aug 24, 2008 9:49 am

I log every fillup and calculate the average for my '84 Westfalia. I have records going back to 2004. My highway mileage, meaning interstate travel at 75mph, is 16-17mpg. My secondary road mileage at about 50-60mph is 19mpg. In town driving is 17 mpg.

My '85 Wolfsbur Edition "weekender" got the same mileage on the interstate and in town, but on secondary roads it would get 21-22mpg. I had it and kept records for 4 years as well.

Sun Aug 24, 2008 11:09 am

Please see the mileage thread via the stickies.

Sun Aug 24, 2008 1:52 pm

You don't mention if you have an auto or 4 speed, automatics get worse mileage.
Still, you should never get less than 15-16, even with an automatic.
Checked the alignment of the tires? That could scrub off enough.
Brake calipers seriously binding? You could jack up each front wheel and see if the tires stops spinning as soon as you release it from a spin.

Sun Aug 24, 2008 6:53 pm

Check the TPS for proper adjustment, check the oxy sensor, check for vacuum leaks.

Sun Aug 24, 2008 7:12 pm

I have talked to a couple of local guys with Westy's and they say they get between 12-13 mpg,seems awful low to me. my 85 Suburban (3/4 ton 4x4) got 12 mpg. on our most recent trip we avg. 18.5 and we were pulling a 350-400 lb. trailer with all the camping gear. plus we had the van loaded with firewood,coolers etc. we went from the Valley to the Coast. it's not a Westy, just a GL with poptop bolted over the big sunroof. installed a new waterpump and t-stat last week,will that help with the mpg's?

Sun Aug 24, 2008 8:20 pm

Yeah, that sounds kinda of odd. My Toyota sequoia gets 14 mpg and it has a v8. My last trip I have a 1.9 l running about 70 mph gets 17-18 mpg. There must be something wrong.

Sun Aug 24, 2008 9:27 pm

I pretty consistently averaged 16 in my syncro adventurwagen over a 15 year period. That was city and highway.

Sun Aug 24, 2008 10:39 pm

<< My last trip I have a 1.9 l running about 70 mph gets 17-18 mpg. There must be something wrong.>>

At 4000 rpm at 70 this sounds like pretty reasonable gas mileage.

If you said 20 mpg at 70 mph, I'd have to call you a prevaricator--- :wink:

Sun Aug 24, 2008 11:22 pm

In my '88 GL automatic this weekend, 285.5 miles on 13.5 gallons = 21.1mpg. Mixed 65 on the freeway and 55 on backroads.

Mon Aug 25, 2008 5:58 am

If GoWesty installed the new 2.3l engine, it seems to me they should figure out and explain why your fuel consumption is so high. Isn't this a warranty consideration?

Mon Aug 25, 2008 7:31 am

Greetings, I second what mordeaux said. Im sure you dropped good money for what you thought would be a good upgrade but the mileage your getting indicates something wrong.
Im good for 15-20 mpg, depending on intown traffic or headwinds on freeway.

Mon Aug 25, 2008 7:46 am

The lowest I have seen is 16. Highest is 22

16mpg was 65mph with a roof box, running the AC, and seven people.

Mon Aug 25, 2008 8:42 am

Again what your seeing has virtually nothing to do with the motor but everything to do with the accessories. A whole lot of them affect the milage and the overall good running of the engine. Just dropping a new motor alone will not improve the performance to like new.

As mentioned, the O2 is critical in giving you the proper mixture when running. The other item that needs to be correct is the fuel pressure regulator. If it runs too high, the ECU will happily keep pumping the fuel it thinks it needs, but is actually pumping in a lot more. The O2 can be come overwhelmed and not let the ECU know what the mixture is, so it goes into a default map. Leaky fuel injectors do the same thing, mixture gets rich because they never shut off. GoWesty normally gives a set of reworked injectors with each engine to keep this problem at bay.

Your rear brakes can also be a problem. When they get a bit on the older side, they tend to drag. Is is due to the rust that tends to form on the shoe arm pivots. Draggy brakes can really hit your milage.

One other milage affecting item is aerodynamics. Is your van shaped like a brick? Seriously, you need to check all the ignition and fuel components to ensure they are preforming to spec. WIth the 2.3 you should be getting between 15-22 depending on your habits and conditions.

Mon Aug 25, 2008 11:17 am

Thanks to all for the input.

GoWesty tells me they checked everything out after the swap, and it was all within normal parameters. However, I noticed the o2 sensor looks pretty vintage. Changing that, and swapping out the cat for a straight pipe (reasonably legal-ish here in the Frozen North) are within my limited abilities to fix, and I've ordered the necessary bits to make that happen. The rest (TPS, vacuum leaks, temp sensor, and draggy brakes) I will leave to those with more talent and experience than I.

Cheers,

Dan

Mon Aug 25, 2008 11:33 am

I'm riding with a completely new exhaust system and a new O2 sensor in a 1.9L manual fully loaded westy that I tend to drive around 65-70 mph on the highway and I get 19-20 mpg