Driving to Big Bend @ 55mph

[badknees]

I get approx the same gas mileage (a little better actually) in my truck doing 70-80 mph going to Big Bend as I do driving to and from work in Houston every day.

55 doesn't work for me.

Everyone worries about the higher speed limit burning extra gas when they should be thinking about the stop and go miles they drive every day. I only make 2 trips a year to BIBE. I commute every day.

[oldfatman]

Badknees it does not surprise me that the traffic in town puts your gas mileage in the sewer. When I was still working in HOuston, I never bothered with figuring fuel mileage around town.  Just pour it in as needed.  From talking with other RV folks and checking the Escapees forum my truck performance at highway speeds seems to be about normal.  Trucks not set up for towing with low gearing and all the other stuff for towing should get a couple of mpg better.  Of course diesel will do better than gas if the vehicles are set up the same since it has more BTU of energy per gallon than gas.  However when I check out the cost per mile it seems gas and diesel trucks do about the same. So if I did not need to tow my home I would likely go back to gas for the ease of finding fuel on the road.

[presidio]

The difference in fuel saving is not worth the added time behind the wheel.

To iterate: Those that want to drive slower already can and do. Those that don't will pay more and more often.

You illustrate my point quite well. However, I wouldn't characterize a 5 mph difference, or even 10, as much 'added time'. Mathematically slower while driving, yes. Saving time when factoring in fuel stops and every other kind of diversion from cruising? Not significant overall. Now if you're comparing doing 80+ (because 80 is just a suggestion for some folks) on I-10 to someone driving 55 on the same road, sure it will make a difference in time and in the wallet.

The windshield GPS navigators (at least my Garmin and I bet others also) have a nice feature that show time in motion, time stopped, total trip time, average speed while moving and average speed over the entire trip. If someone regularly drives a long stretch of road....on the order of several hundred miles (because doing this over 50 or 100 miles isn't representative and most certainly skews the results toward high speed for short distances)...it would be instructive to see what the total trip data is for 80 mph on I-10 vs. 55, 60, 65 and 70.

Once again, factoring in stops and traffic issues, I think the experimenter would find there is not a lot of time saving at the higher speeds, but cost would be higher. You can't just use the raw speed without considering the whole package. Now, there is no doubt that the result at 55 will be noticeably slower (and dooms 55 limits as it is seen as unacceptably slow), but the other speeds would likely not be linear improvements in time though the fuel costs would increase along with the well known effects of wind and tire resistance as speeds increase.

On several cross country trips I seem to end up averaging around 60 mph overall regardless of cruising speed. That is a recollection and not a result of the empirical testing I suggest above. However, it does include cruising at 65 to 75, though as I mentioned earlier, I have pretty much scaled back to a consistent 65.

[SHANEA]

As a general rule, I stop for two things - feed petrol to the beast and rest room breaks.  Otherwise, it's pedal to the metal.  I do my best to minimize the downtime.  Sometimes a quick run through the Sonic for some iced tea, which has the knock on effect of increasing the rest room breaks.      I also try to get onto I-10 ASAP to maximize the high end speed limit.  Interesting, when I was coming back from Atlanta recently, all of the I-10 speed limit signs in other states did not back it down from 70mph to 65mph at night. 

[EdB]

I get approx the same gas mileage (a little better actually) in my truck doing 70-80 mph going to Big Bend as I do driving to and from work in Houston every day.

I had a little rental car this past week that showed my overall gas mileage as well as instantaneous gas mileage. So I did a little experimenting, and I didn't see much difference between 55 and 70 either. In fact, the 70 mph was slightly better mileage on the highway. Worst gas mileage was driving really slow on the dirt roads, best was 99 mpg coasting downhill.

[mule ears]

I had a little rental car this past week that showed my overall gas mileage as well as instantaneous gas mileage. So I did a little experimenting, and I didn't see much difference between 55 and 70 either. In fact, the 70 mph was slightly better mileage on the highway. Worst gas mileage was driving really slow on the dirt roads, best was 99 mpg coasting downhill.

What kind of car was it Ed?  And from what rental company?  I've never had a rental that had that kind of electronics.

[EdB]

What kind of car was it Ed?  And from what rental company?  I've never had a rental that had that kind of electronics.

Chevy Cobalt, I think, from Avis. It was a little info button right beneath the cruise control stuff. I didn't discover it until I'd had the car for 5-6 days myself, then I couldn't stop looking at it and looking at all the readouts. They showed up in the same place as the temp/odometer reading. If I can remember right, there were readings for mileage for Trip A and B, overall average mpg, instant mpg, overall average speed, # of miles left for the current tank of gas. Might have been one or two more that I can't think of.

[oldfatman]

Sounds like the same readout as on my truck and several friends GM cars and suv's. It is fun to play with.

[RichardM]

My wife's new Honda CR-V has a real-time constant display of current mpg displayed as a bar at the top of the main display. It goes from 0-60. Kinda disheartening watching it go to zero whenever you come to a stoplight. The car will also display trip info, but I haven't had a chance to play with it.

[elhombre]

It just showes you  how stupid these Jacka##'s really are.  They aren't any smarter than most 18 year olds.  In the 70's there was an actual gas shortage due to opec troubles (embargo).  We have plenty of gas to go around right now at the price you pay.  Those congressmen think that we the people are paying too much so they are going to increase supply by reducing our useage through speed limits.  They won't let us drill for more oil, but they have no problem screwing us by regulating our life more.  If this monkey was so concerned about my cost of living increasing, why don't they make the tax reductions permanent and quite printing money for economic stimulus or extending unemployment checks.  The main reason we are paying so much is because government is causing inflation.  The lack of education in our country is the root cause for allowing the crop of current and potiential leaders to get away with these ideas. 

I will remove myself off the soap box now.  I'm going to the coast next week and then, it will all be better. 

[presidio]

Interesting, when I was coming back from Atlanta recently, all of the I-10 speed limit signs in other states did not back it down from 70mph to 65mph at night. 

TX is the only state I can recall which has a night speed limit. It also is the only state that posts those huge  billboards at state lines with a menu of speeds depending on what you are driving and when.

[presidio]

What kind of car was it Ed?  And from what rental company?  I've never had a rental that had that kind of electronics.

I've had several rentals with such displays. Can't say offhand which models but I only rent the smallest, cheapest things available in the compact category. These have included Hyundai, Chevy and Ford. They also will show miles to empty and other things like when oil changes are due and various temperatures.

[Undertaker]

Since I spend a lot of time behind the wheel, I monitor both time and fuel, while in Houston, I coast when possible, and try to stay moving, stop and go kills mileage. I may at some time consider not traveling to the Bend (distance and fuel) but for now I will pay the difference to spend more time in the Bend. On the way back different situation. Spent the fourth around the pool at home and will spend more weekends not traveling, I already spend around a 700-1000 miles a week in the Houston area at slow speeds. I have driven 55 across Texas, not as easy as 55 in New York. Cost v Benefit.

[presidio]

I have driven 55 across Texas, not as easy as 55 in New York. Cost v Benefit.

How did you ever get up to 55 in New York (City?)?

[10ftTall&BulletPrf]

Mythbusters did a show where they proved you could improve your gas mileage by 75% just by following 20ft behind a trucker.

SOLUTION: Every BIBE traveler gets assigned a trucker to follow!

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