Date: Mon, 27 May 1996 10:17:23 -0700
Sender: Vanagon Mailing List <vanagon@vanagon.com>
From: jwakefield@4dmg.net (john wakefield)
Subject: Re: good ole' Chevron Techron
Paul wrote:
"I sprung for a bottle of Chevron Techron. It was the 1st time I've
ever used it in my 79 bus. I drove with it in a full tank, then refilled
again today for the 2nd time since using it. I thought I'd let you all
know my city mpg has jumped up to *25*. Before using the Techron,
driving in stop/go traffic, I would only get 17 mpg. . . . . .
but the fuel economy has gotten MUCH better, wouldn't you say!"
Paul, I don't want to rain on your parade, but you did ask. Divide 25
by 17 to see you're talking about a 47% improvement. Ok, so I'm
mentioning too many significant digits, but the order of magnitude cannot
be caused by the bottled additive Chevron Techron. I've chased
incremental performance enhancements for many years, especially during
the 17 years I competed in drag racing and briefly held national records.
Now, I compete with my previous record of recorded mpg with each fill to
the last penny top fill. Synthetics like Mobil 1, Syntec, and Amzoil
will give you a solid 2% mpg gain.
I'm vexed by not being able to go back to an assured "pre treatment
condition" on some of the "slick" products, but I'm very skeptical about
whether or not they do any good. I talked with one professional motor
rebuilder who's rejected a warrantee claim on an engine that had an oil
passage blocked with a bunch of this stuff. You look at the performance
of different oil filter brands tested to learn the threshold particulate
size beyond which they won't pass (and they do vary) even when they are
new and least restrictive, and you may question the idea that this stuff
has enough time to "plate" the wear surfaces as claimed before it's just
captured by your oil filter. As to how this stuff could form a small oil
passage block, I've no idea. But at this point I'm pretty well convinced
that it can happen.
I've read every book I've encountered about how to improve milage, some
by performance trials winners who share their techniques. Lots of these
tricks really work. Perhaps you've pumped your tires up hard, gotten
them aligned, are practicing fairly aggressive starts with super early
shift points just above "lugging." These work. Perhaps you're not
rushing to red lights like an idiot and started timing them for some
reason, an engaging game when other drivers are eager to steal your
safety margin space ahead. Perhaps, the rigor of your measurements
accounts for this. I've run several vehicles with instantaneous mpg
displays, and have one now. Trust me, you cannot trust odometers,
speedometers, or fuel tank gauges. Interstate mile markers over minimum
10 mile spans are useful and 100 miles are better with a stop watch, note
pad and calculator. Mechanical speedometers aren't even linear in their
errors! At least odometers are. Fuel gauges can be calibrated by you,
using your known mpg history and odometer observations after a fill to
the last penny fill, but are useless in computing mpg. When
someone says "and it only took a quarter of a tank" it says a lot
about them and little about fuel usage. Carney operators look
for fools like them every day. Absolute fill to absolute fill is all
that counts. The auto pump shut off occurs at different points with the
same pump on the same car. My Lincoln Continental can take up to $3
worth of additional diesel fuel after a pump automatically quits. It
varies a lot. Try to factor that kind of variation into fuel consumption
records. It doesn't work.
Sorry if this sounds like I'm trying to rupture your balloon, but I
love efficiencey and if this stuff works as you describe, I'll become an
eary adopter and happily post my apology for being too skeptical.
Just to weigh in on the MPG poll, dropping insignificant digits to
comply with the group norm, I've gotten as low as 27 mpg and as much as
34 mpg with a '83 diesel Westie around town. Florida is flat and I hate
touching that brake peddle. This is not the result of a casual effort,
though I don't hold up traffic.
John Wakefield
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