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Almost did it!

I topped off, loaded family of 6 and luggage for a swim meet on the other diagonal corner of Oklahoma (north of Tulsa) last weekend. I didn't expect to break our personal best, given we got lost, motored a while around Bartlesville before finding our hotel...then spent the next day in town, shopping and eating after the meet.

On the way back it looked like I was going to break my record. I rolled into Lawton (59 miles from home) with 540 miles on the odo...the low fuel light had illuminated about 20 miles previously, so I knew I could make it home. However, the wife was insistent...get a couple gallons, make the light go away! :frown:

I will join that 600-mile club one day.

OF
 

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I took almost all seats out, lazy Susan, trailor hitch, roof
chicken wires, and lowered suspension with H&R springs on
my 2006 EXL-RES, so I don't think it is fair to post my MPG in 500 Mile club :)
 

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Ok, here we go: 905 Km, which is 562.3 miles and filled up tank with 80 liters-
-fuel pump hose clicked off at 70 liters, and I usually put in an extra 10 l.
I had to go downtown TO, and so 80Km or so, were driven a little too hard.

I know now that I can reach 1000 Km (621 miles) If I drive very smoothly, no FASing ever.
Again, almost all seats out, except front and one captain chair in the second row.
Suspension lower by 1.5" with H&R springs (big difference, almost no body roll), and tire pressure at 35psi. No junk in the trunk.
Also, I do not use ethanol on my cars, so Shell 91 only.
 

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....I know now that I can reach 1000 Km (621 miles) If I drive very smoothly, no FASing ever...
Now THAT is what I call a 1000km challenge. I think the Porsche 956's in the pic below only get 3mpg in endurance trim.



...Also, I do not use ethanol on my cars, so Shell 91 only.
I never thought about that...use 91 octane. I'm always using 86 or 87, and the engine adjusts the spark curve and fuel delivery to match it.

Next endurance run note to self: use the better fuel.

OF
 

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Discussion Starter #226
I don't see how lowering your van is supposed to equate to better mpg. You block off the surface area of the tires barely but I would think the air pressure under the vehicle would increase due to reduced area for air to flow. I would think the increased air pressure would contribute more drag than blocking the tire profile a bit, but let's just call it a wash. Its not like you have an under tray to smooth the air flow and reduce air pressure...

What's your reasoning to think you'll get increased mpg by lowering it?
 

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Discussion Starter #227 (Edited)
OF, if you can find fuel with no ethanol, I believe it will actually yield better mpg. But maybe not measurably so, unless we were being scientific and had access to a test track and such. I know JDS is right about that ... I've done the research.

As for the octane ... I've heard of some Accords (maybe a few years back) stating in their owner's manuals that they had something like 5 more hp running 93 octane. That implies that on 86 or 87 octane, the knock sensor will detect some knock and as a result the ecu retards the timing to eliminate it.

If us Ody owners could determine that our ignition timing is not working at maximum advance while using 86 or 87 octane, then there might be some mpg gain with running 93 if the timing would be adjusted more advanced. Normally i'd just say running 93 octane is a waste of money, but after what was in the Accord owner's manual, I don't know ... there may be some merit in it. I doubt the mpg would ever increase enough to justify the additional cost of premium, but it may be what's needed to bump a few folks into the 600 mile club. :D

I do have one station that has 93 octane with no ethanol, and is what I run in my RX-7. If I had any known trips coming up, i'd try to break my own 600+ mile record. But as my sons get bigger, they just want "to get there." Which causes me to drive much faster eliminating my chance to see a new record.

I'm back to driving my Corolla, and trying to hit 40 mpg with it! Its a lot of fun! :D


JyRO
 

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Mine gets nothing but 94...........Trust me.....it does nothing to help mpg
Oh, baloney, WW...it helps your lead-foot wife go faster. :D

OF
 

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I don't see how lowering your van is supposed to equate to better mpg. You block off the surface area of the tires barely but I would think the air pressure under the vehicle would increase due to reduced area for air to flow. I would think the increased air pressure would contribute more drag than blocking the tire profile a bit, but let's just call it a wash. Its not like you have an under tray to smooth the air flow and reduce air pressure...

What's your reasoning to think you'll get increased mpg by lowering it?
Lowering the car with the H&R springs does help MPG in 2 ways:
Less underbody air turbulence and less up and down movement.
Think NASCAR or F1, for example.
 

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OF, if you can find fuel with no ethanol, I believe it will actually yield better mpg. But maybe not measurably so, unless we were being scientific and had access to a test track and such. I know JDS is right about that ... I've done the research.

As for the octane ... I've heard of some Accords (maybe a few years back) stating in their owner's manuals that they had something like 5 more hp running 93 octane. That implies that on 86 or 87 octane, the knock sensor will detect some knock and as a result the ecu retards the timing to eliminate it.

If us Ody owners could determine that our ignition timing is not working at maximum advance while using 86 or 87 octane, then there might be some mpg gain with running 93 if the timing would be adjusted more advanced. Normally i'd just say running 93 octane is a waste of money, but after what was in the Accord owner's manual, I don't know ... there may be some merit in it. I doubt the mpg would ever increase enough to justify the additional cost of premium, but it may be what's needed to bump a few folks into the 600 mile club. :D

I do have one station that has 93 octane with no ethanol, and is what I run in my RX-7. If I had any known trips coming up, i'd try to break my own 600+ mile record. But as my sons get bigger, they just want "to get there." Which causes me to drive much faster eliminating my chance to see a new record.

I'm back to driving my Corolla, and trying to hit 40 mpg with it! Its a lot of fun! :D


JyRO
A few years back when I first bought the 911, I went through the
Ethanol discussion and research at the Porsche forum. Ethanol does
less harm to modern vehicles, however, still not healthy to rubber hoses
and poly plastics used in the fuel injectors, fuel pump, seals, etc.
The best source of info for Ethanol is the actual government documents,
which I use to have the link for- just Google it.

Even Porsche themselves would not print that it was good for the
vehicles, only that the modern materials were more compliant.
Use it if you want, it's your car.

Also, I enjoy not having the black gunk on my exhaust.
Extra cost? What, 3 bucks per tank or so?
 

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For more accurate MPG measurement, I use a free iPhone app
called Road Trip Lite. Even if you don't fill up the tank every
single time, it does a perfect average of all tanks, which
no one ever calculates.

EDIT: so it gives you two averages: one for the last tank
filled or not, and one for all tank refuels up to date.

The more you use it, the closer you get to the real average MPG.
 

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Discussion Starter #233
Lowering the car with the H&R springs does help MPG in 2 ways:
Less underbody air turbulence and less up and down movement.
Think NASCAR or F1, for example.
I'm convinced. :rolleyes: I don't believe that up/down travel of the vehicle is created by any energy other than what pavement undulations load into the suspension. NASCAR and F1 (or any other racing) do not lower their vehicles for mpg, they lower it primarily for handling. Airflow is improved with underbody plastics. Therefore I still see no reason up/down travel of the suspension would lead to increased fuel useage. For a VAN on stock suspension, my Ody is quite stiff.

When my wife let's me know that she wants to autocross through the Publix parking lot, carving her way around pedestrians & shopping carts in order to beat Sienna's to the prime parking spaces, then I'll consider lowering the van. :D
 

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Lowering the car with the H&R springs does help MPG in 2 ways:
Less underbody air turbulence and less up and down movement.
Think NASCAR or F1, for example.
How do you know it's less turbulence? Or not? That area in front of the A/C condenser is just one big plenum, with air exhausting underneath (and often spilling out to the sides). If you want to reduce drag, it has to be a comprehensive approach so that you don't make things worse.

OF
 

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If the height of the vehicle was zero, your turbulence would be zero.
:D You mean it wouldn't run! You still have a huge, huge plenum in front of your heat exchangers (A/C condenser and radiator) that exhausts into the space under the car, ejecting air aft of the front wheels and out the sides. Lots and lots of turbies from just this, and on a hot day you need this air flow, turbulent or not. More or less turbulence after lowering ...better or worse drag? ...who knows.

Also, it's not smooth at all under our "F1 Odys" ;). How do you know you're not counting on a somewhat-boundary layer of relatively slower moving air close to all the underfloor mechanicals to keep drag down at stock height? How do you know that lowering our vans won't, at the end of the day, add some drag down there?

None of the answers are as simple as we like. One of the proven answers for any car is to block all your heat exchangers, making Ody's nose perfectly smooth...and adding variable flaps to let in just the right amount of air for heat exchange. Seen some guys do this to their Hondas, with quantifiable results.

Of course, I won't go that far. Properly inflated tires are a known MPG enhancer (or maintainer). Watching throttle lever angle pays dividends (or just be mindful of how much you depress the gas pedal for us without Scangauges). Getting rid of the roof rack also helps, like you've done.

It's all big fun, at least for me, to try and get the most out of senor Ody.

OF
 

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:D You mean it wouldn't run! ...
The porportion was just to answer your question of how do I know
lowering a car decreases the turbulence. :)
Lower space, means less air and less turbulence.

...How do you know that lowering our vans won't,
at the end of the day, add some drag down there?...
These are well known facts, and not just on our vans.

... Lots and lots of turbies from just this,
and on a hot day you need this air flow, turbulent or not...
:huh: You do not cool a vehicle by increasing under flow turbulence,
that is what radiators are for.

I enjoy the van lower, lighter, with better handling and with better FE.
 

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... You do not cool a vehicle by increasing under flow turbulence,
that is what radiators are for..
Never said we needed turbulence. It's just there (lots of it) with the way the Ody is designed, whether we like it or not.;)

When it comes to lowering and drag reduction, you just don't know. Lowering a van with a "dirty" underpan is not the automatic drag reducer that we think it might be if you don't "finish the job"; like, by adding an air dam and/or blocking parts of the plenum to keep air out...you don't know, I don't know. It could cause us to get a small increase or decrease in drag. Can't tell...unless, of course, you tell us my Ody really is built like an F1 or NASCAR racer; or you have your own personal wind tunnel and have been hiding this fact from us. Hey, in that case, why aren't you sharing some tunnel time with us fellow clubbers, mister?! :nothappy:

However, I do know you made a lot more "money for the company" by removing your roof rack and taking away all that weight and not carrying a family of 8. I'm looking at getting rid of the rack...have only used it a few times, and that was long ago. Big family...I have to "grow" out of that one.

We'll see if I can get to 600 miles before you do. Not counting on it, with my somewhat smaller (by 1 gallon, IIRC) Gen 2 gas tank and no VCM, but I will be trying.

I'd pay good money to see an odometer with 1000km on it...now THAT is a nice round number.

OF
 

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Discussion Starter #240
NOPE! The secret is in the fill, and the technique of throttle application and timing.
 
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