Honda Car Forum

http://www.mpdirect.com/index.asp?Pa...23&dc=mpgoogle

Is this some kind of joke?

<mmdir2005@yahoo.com> wrote
>
http://www.mpdirect.com/index.asp?Pa...23&dc=mpgoogle
>
> Is this some kind of joke?

I'd say it's some kind of snake oil, yes.

Raising octane has to do with reducing engine knock. If this stuff really
raises the octane, and you have engine knock, then fuel efficiency may
improve. If it cleans the fuel system, that might help fuel efficiency, too.

Otherwise, I doubt it will help fuel mileage.

All I do these days for the fuel system is change the fuel filter regularly
and add a $6 bottle of Chevron Techron to the fuel tank, per the bottle's
directions, once a year. It's supposed to keep the injectors etc. clean.
(Some add this every oil change.) Dunno if it makes a difference, but some
folks here suggest it does. My 1991 Civic is getting up there in years, and
some parts about which the typical "trade my car in every five years" owner
need not concern him/herself, are getting a bit mucky. Hence my attempts at
prevention of the muck. Still getting 40+ mpg most of the year, so I can't
complain.

I don't know how your 91 civic could reach 40+ mpg. No matter how good
you maintain
your car, 90 civic can't reach more than 35mpg.

mmdir2005@yahoo.com wrote:

> I don't know how your 91 civic could reach 40+ mpg. No matter how good
> you maintain
> your car, 90 civic can't reach more than 35mpg.

Well guess what? Hers can get 40mpg. It depends on your driving habits.

EPA rated the 1990-93 Accord at 28mpg on the highway, but I consistently get
32-34mpg on the highway with my '93. And it's an automatic.

You're mistaken. There are many reports on groups.google of early 90's
Civics (1.5 Liter, no air conditioning, manual transmission) reaching 40+
mpg. I checked. In addition, since someone else challenged me on this a
while back, I have kept careful records for the last year of each fillup
(almost alway over 8 gallons) and the mileage.

<mmdir2005@yahoo.com> wrote
> I don't know how your 91 civic could reach 40+ mpg. No matter how good
> you maintain
> your car, 90 civic can't reach more than 35mpg.
>

Elle wrote:

> You're mistaken. There are many reports on groups.google of early 90's
> Civics (1.5 Liter, no air conditioning, manual transmission) reaching 40+
> mpg. I checked. In addition, since someone else challenged me on this a
> while back, I have kept careful records for the last year of each fillup
> (almost alway over 8 gallons) and the mileage.
>
He's going by EPA's estimates. EPA rated the 4th-gen Civic LX 5-speed at
35mpg on the highway. I find that although EPA may overestimate mileage on
some cars, they tend to underestimate mileage for Hondas. As I said before,
my '93 Accord (automatic) gets much better highway mileage than EPA
estimated, and I have seen many posts from others who get similar mileage.

"High Tech Misfit" <me@privacy.net> wrote
> Elle wrote:
>
> > You're mistaken. There are many reports on groups.google of early 90's
> > Civics (1.5 Liter, no air conditioning, manual transmission) reaching
40+
> > mpg. I checked. In addition, since someone else challenged me on this a
> > while back, I have kept careful records for the last year of each fillup
> > (almost alway over 8 gallons) and the mileage.
> >
> He's going by EPA's estimates. EPA rated the 4th-gen Civic LX 5-speed at
> 35mpg on the highway. I find that although EPA may overestimate mileage
on
> some cars, they tend to underestimate mileage for Hondas. As I said
before,
> my '93 Accord (automatic) gets much better highway mileage than EPA
> estimated, and I have seen many posts from others who get similar mileage.

Sure. I also agree with you that driving habits play a role. The EPA tests
on a treadmill, too, right? Maybe it simulates hills, but it's still not as
though it duplicates my driving habits and terrain.

Plus I have a vague recollection of some chatter on the net about EPA
testing being done only on young cars. I suspect there is some "break-in"
that occurs that, with a properly maintained vehicle, will result in higher
mileage from, say, 100k miles to 200k miles, vs. the fuel mileage pre-100k
miles or so.

For several months recently I was doing a lot of coasting on (not steep, not
very long) hills, letting the RPM drop to idle, thinking I was saving gas.
But I read here that the engine control system does xyz in idle which is not
as efficient as keeping the RPMs higher (using engine braking) on a hill.
Plus, in the last few months I also strive to keep the RPM under 3000 at all
times (which means on the highway, I'm limited to about 65 mph, tops). These
seem to have helped. I will continue the experiment and see if I can build
higher statistical confidence in this theory with more data.

For the record, I only started adding Chevron Techron last year, around 15k
miles ago. It's really a gamble, but I figure it could not hurt. Perhaps my
biggest motivation for adding it is that I had a severely plugged PCV valve
(the original one, never been touched before) in 2003. Replacing it made a
10-15% difference in mileage, consistent with discussion on the net and in
Chilton's manuals. Now I inspect it every oil change and spray some PB
Blaster into it. I plan to replace it every so often, like every seven
years. If my car lasts that long.

I have always been religious about oil changes. Did them at 3k-4k miles/6
months for years but switched to 5k miles/6 months around 2000. Stayed on
top of air filter, fuel filter, coolant, plug and wires, and timing belt
changes, too, per the maintenance schedule. Always used unleaded regular
gas.

Elle wrote:
> "High Tech Misfit" <me@privacy.net> wrote
> > Elle wrote:
> >
> > > You're mistaken. There are many reports on groups.google of early 90's
> > > Civics (1.5 Liter, no air conditioning, manual transmission) reaching
> 40+
> > > mpg. I checked. In addition, since someone else challenged me on this a
> > > while back, I have kept careful records for the last year of each fillup
> > > (almost alway over 8 gallons) and the mileage.
> > >
> > He's going by EPA's estimates. EPA rated the 4th-gen Civic LX 5-speed at
> > 35mpg on the highway. I find that although EPA may overestimate mileage
> on
> > some cars, they tend to underestimate mileage for Hondas. As I said
> before,
> > my '93 Accord (automatic) gets much better highway mileage than EPA
> > estimated, and I have seen many posts from others who get similar mileage.
>
> Sure. I also agree with you that driving habits play a role. The EPA tests
> on a treadmill, too, right? Maybe it simulates hills, but it's still not as
> though it duplicates my driving habits and terrain.
>
> Plus I have a vague recollection of some chatter on the net about EPA
> testing being done only on young cars. I suspect there is some "break-in"
> that occurs that, with a properly maintained vehicle, will result in higher
> mileage from, say, 100k miles to 200k miles, vs. the fuel mileage pre-100k
> miles or so.
>
> For several months recently I was doing a lot of coasting on (not steep, not
> very long) hills, letting the RPM drop to idle, thinking I was saving gas.
> But I read here that the engine control system does xyz in idle which is not
> as efficient as keeping the RPMs higher (using engine braking) on a hill.
> Plus, in the last few months I also strive to keep the RPM under 3000 at all
> times (which means on the highway, I'm limited to about 65 mph, tops). These
> seem to have helped. I will continue the experiment and see if I can build
> higher statistical confidence in this theory with more data.
>
> For the record, I only started adding Chevron Techron last year, around 15k
> miles ago. It's really a gamble, but I figure it could not hurt. Perhaps my
> biggest motivation for adding it is that I had a severely plugged PCV valve
> (the original one, never been touched before) in 2003. Replacing it made a
> 10-15% difference in mileage, consistent with discussion on the net and in
> Chilton's manuals. Now I inspect it every oil change and spray some PB
> Blaster into it. I plan to replace it every so often, like every seven
> years. If my car lasts that long.
>
> I have always been religious about oil changes. Did them at 3k-4k miles/6
> months for years but switched to 5k miles/6 months around 2000. Stayed on
> top of air filter, fuel filter, coolant, plug and wires, and timing belt
> changes, too, per the maintenance schedule. Always used unleaded regular
> gas.
+++++++++++++++++++++++++++
I found the device at this link
<http://www.ggimages.com/rx7/pwm.html>
to be a very nice additon. I had to build 2 because my Civic has
DPFI, and you have to monitor both the primary and aux injector.
It was very educational to see just when the primary and aux
opened.

I found that keeping the engine RPM low helped most of the time, but
at times it was better to downshift and run at higher RPMs. Very
counter intuitive.

If you shop around you can build the whole thing for less then $10 a
channel. For a multiport, IE 4 injectors, just monitor one, the
ever so slight error is not worth another $30.


Terry