What MPG could I hope for?

[superchow]

I'm heading to a family event 1700 miles away in a few weeks and it got me thinking. Elevations tend to be between 5000 and 7000 ft once in CA, which means signifiantly lower air resistance. What sort of mpg could I expect to get with the following criteria:

Average speeds of 55-60 mph (i.e. including stops for sightseeing, eating, "pitstops"), driver and one passenger and some luggage. Car: 2007 Honda Civic EX with MT. No mods per se, just inflated tires to (sidewall max) 44 psi and using many hypermiling techniques. (Limited use of P&G due to average speeds).

The route goes from Olympia, WA to Redding, CA. Then via Hwy 50 to Arches NP in UT, and finally north to Rock Springs, WY.

I was conservatively estimating 40 mpg, but I'm hoping for something more like 45. Comments?

[Ptero]

The biggest single thing you can do is find NO ETHANOL gasoline. I just ran Hwy 6 from Bishop California to Chicago Illinois in a Smart Pure ForTwo pulling a Featherlite aluminum trailer. In Bishop, the Paiute Indian Casino has NO ETHANOL premium. I filled up there and drove to Ely Nevada. I used the simplest hypermiling technique of COASTING DOWNHILL, and the very simple CONSTANT THROTTLE technique, the slightly less-intuitive FOOT-OFF THROTTLE on very steep grades, CRESTING HILLS AT MINIMUM SPEED, MAX PSI SIDEWALL and NO BRAKING or AIR CONDITIONING.

Combined, these techniques rewarded me with 59.3 mpg.

NO ETHANOL - Ethanol robs about 30% MPG from engines tuned for gasoline.

Note: Some of these techniques can only be done safely in certain places and under certain circumstances by the observent and skilled.

CONSTANT THROTTLE - Hold your throttle constant for your chosen cruising speed on a level road and let the hill drag down your rpms. Shift into a lower gear without accelerating, hitting the max torque peak specific for your engine and letting the hill drag down your rpms until you downshift again to the same torque peak rpm for the next gear down. Never accelerate uphill. I'm talking torque, not horsepower. Horsepower is a different game and has nothing to do with hypermiling.

FOOT-OFF THROTTLE - Leaving the transmission in a high gear while descending steep grades cuts the injectors. It is safer but not as much fun (nor as effective in MPG) as squealing around blind corners in neutral with your passenger(s) screaming.

CRESTING HILLS AT MINIMUM SPEED - Technically speaking, any speed you carry over the top of a hill and into the next descent is wasted energy, provided by gas you didn't have to burn.

NO BRAKING - Same as above. Braking = wasted gasoline.

AIR CONDITIONING - ~17 horsepower in gasoline is lost during operation. Drive naked.

[superchow]

Originally Posted by Ptero

The biggest single thing you can do is find NO ETHANOL gasoline.
...
AIR CONDITIONING - ~17 horsepower in gasoline is lost during operation. Drive naked.

I didn't realize that no ethanol gas still existed! Never thought of that - love this forum!

With regards to driving naked... well, let's just say that I do not look as pleasing as the "biker chick" from Vanishing Point. But if possible I'll turn off the A/C. In somewhat muggy weather here in WA I can generally stand to keep it off to about 80-85 degrees.

Thanks a bunch for the complete reply!

[Ptero]

AREAS TO AVOID IN CROSS COUNTRY MPG TRIPS
courtesy of ExxonMobil

ETHANOL IS FORCED ON CONSUMERS OF SEVERAL STATES, REDUCING MPG BY ABOUT 30%. ALL OXYGENATED GASOLINE CONTAINS ETHANOL. FUEL UP OUTSIDE THESE AREAS FOR DRAMITIC MPG GAINS!

http://www.api.org/aboutoilgas/other...ements_Map.pdf
http://www.exxon.com/USA-English/Fil...p%20100102.pdf

I didn't realize that no ethanol gas still existed! Never thought of that - love this forum!

SUPERCHOW, LOTS OF GOOD INFO ON ECOMODDER! : )

[superchow]

So we made it back in one piece and I am am somewhat gutted by the mileage we got during our trip. Granted, we had many miles to drive, lots of things to see and we didn't want to drive too much time in the darkness to avoid hitting a deer.

I believe we averaged about 37 mpg, which isn't bad, but given the high altitude (5000+ ft) and warm weather (80s) and theory of higher energy content non-ethanol gasoline in CA, NV and UT I was hoping to break the 40s consistently even when driving fast (65+ mph).

Here some factors I attribute to the missed goal:

1) Even a little bit of weight affects our car. 200 lbs of luggage is roughly 6-7% of our car's weight. With only 128 ft-lbs helping to lug 3200 lbs over mountain passes the engine has to work hard.

2) We had to keep the A/C on for a good chunk of the time. My wife was roasting in the sun...

3) Cross-winds! We had strong winds from the south-west which is a major factor when driving at high speeds.

4) High altitude. To keep some level of performance the engine had to be kept in a lower gear around town (2nd and 3rd instead of 3rd and 4th) and passing and passes had to occur in 3rd and 4th gear. I feel for any Civic owners in the Rockies! Strangely after 400-600 miles or so it seemed the car felt spunkier again. Maybe just my mind playing tricks on me, or maybe the ECU re-mapped itself to compensate?

The non-ethanol gasoline was a let-down. No change noticed. The altitude made much more of a difference to "engine feel", or as I like to call it - elasticity. Here in western Washington it feels lively and elastic. In Wyoming the engine needs revs to be motivated to pull the car.

On our trip back home we averaged 73 mph over 14.5 hrs, so I think we can be satisfied with 37ish mpg. Comments welcome. (Previous commnts appreciated!)

[superchow]

By the way - if anyone is in to Top Gear from the BBC - let me know if you've seen the American "Muscle Car" Special that aired last year. This trip turned into an impromptu pilgrimage of sorts.

[Ptero]

The non-ethanol gasoline was a let-down. No change noticed.

energy content
ethanol HHV = 84,000 Btu/gallon
gasoline HHV = 125,000 Btu/gallon
The energy content of E10 is approximately
(.10 x 84,000) + (.90 x 125,000) = 8400 + 112,500 = 120,900 Btu/gallon
This is a loss of
125,000 - 120,900 = 4100 Btu/gallon or 3.28 percent

To accurately determine the loss, you would need to run a tank of E10 and a tank of straight gas over the same route with the same driving style. I have done that with several vehicles on round trips on Hy 40 between Los Angeles and Albuquerque, starting with full tanks of California E10 and fueling again with straight gas in eastern Arizona.

The numbers don't lie.

[roflwaffle]

Originally Posted by Ptero

I have done that with several vehicles on round trips on Hy 40 between Los Angeles and Albuquerque, starting with full tanks of California E10 and fueling again with straight gas in eastern Arizona. The difference is VERY noticeable.

The numbers don't lie.

Where specifically do you fill up?

[Ptero]

From stations supplied by refineries owned by Indian tribes.

[superchow]

Originally Posted by Ptero

To accurately determine the loss, you would need to run a tank of E10 and a tank of straight gas over the same route with the same driving style. ... The numbers don't lie.

I agree. The test was hardly scientific. Unfortunately California is just too far away for a quick "jaunt" on a weekend to perform a better test. Does California have winter blend gasoline too?