Re: [T3] long distance gas mileage experiment

[Jens Vagelpohl <jens@type4.org>]

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On 5 May 2006, at 04:51, Jim Adney wrote:
> > I *Think* the Taurus has an AFC based system, do you
> > think your good gas milage was more because of the FI system than the
> > thinner air to drive through?  Is this also true of the Squareback?
>
> I think the Taurus uses a hot wire sensor, but I'm really not sure.
> I'm almost completely ignorant of it, which annoys me, but everything
> I've tried to do on it has turned out to be incredibly difficult
> (more than 1 hour to replace a center brake bulb, drop the engine to
> replace the alternator, etc.) I suspect that whatever the Taurus
> uses, it accurately measures air mass, so it should meter gas
> appropriately regardless of altitude.

If it uses the hot wire than it truly measures air mass, and would  
act correctly as air thins out. Simple AFC systems with the flap- 
based sensor cannot react as precisely to air thinning out, I believe  
some L-Jetronic engines actually had separate height compensation  
devices.

Speaking of long-distance driving and recording gas mileage, I still  
have my hand-written notes from 1995 when I drove my 412 wagon (L- 
Jetronic) from Midland/MI to San Francisco, San Diego and back. I  
went north through the UP, crossed it to Duluth and joined I-94 in  
Fargo/ND. Straight shot west to Seattle, then I-5 South to Grants  
Pass and US-101 to San Francisco. My best tank yielded 24.5 mpg, and  
the worst just under 20. In total 3045 miles averaging 22.25 mpg. And  
the gas was averaging about $1.30/gallon.

The route back from San Diego went east on I-10, changing to I-20 in  
western TX, I-30 in Dallas/Ft Worth, I-40 in Little Rock/AR, then  
I-65 in Nashville and I-71 in Louisville, picking up I-75 for the  
home stretch in Cincinnati.

When I got home I had clocked up a total of 8724 miles in 3 weeks,  
burnt 390 gallons of regular unleaded fuel with an average of about  
22.4 mpg, and used 7 quarts of oil (the engine was leaking a little  
bit then, but cured itself on this trip). The only problem I had was  
the typical VW malady where the solenoid sticks due to voltage loss,  
I kept an old piece of carpet in the car to crawl underneath and tap  
the solenoid.

It looks like I might be doing a true ocean to ocean cross-country  
trip in July, from Salem/OR to just south of DC. This would be to  
purchase and drive home a 1976 Porsche 914, coincidentally a 1.8  
model which has the exactly same engine that my 412 wagon has, plus a  
catalytic converter.

jens

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