Fuel economy ideas and MPG Boosting (merged threads)

[Paul Mayeux]

Originally Posted by ipso_facto

I hear that best MPG is where the HP and torque curves intersect. For my 7.5L engine and auto, it's 2200 rpms. Which usually means 47mph. I have gotten almost 12 mpg once like that. Usually it's 10 empty.

I would love to own a 5 speed due to reduced rpms. 3 speed automatic and big block does not lead to good mpg.

A Gear Vendors under/overdrive would work good in your case. I was looking at their products on their website and it sounds like a pretty good system, especially if you've got a 3 spd.

I have the same engine but with a 4sp auto with 4.10 gears and I get about the same mileage 10.5 to almost 12 empty and about 8.5 towing. At 60 in OD I'm running about 1850 rpms.

[2airishuman]

fuel additives

i realize this is a big can of worms and i'm as doubting as most educated folks when it comes to a magic juice.....but

i've used the stanadyne all season performance formula fuel additive with positive mileage results.

my powerstroke is still new (6 months/16,000 miles) and i decided to try the stanadyne at about 500 miles into ownership. with long trips, tires maxed and no trailer in tow it seemed to boost mileage 2-2.5 mpg or so on the highway (i alternated tank fulls for 3000 miles) and less with mixed/city driving...1 mpg or so.

with towing these last 11000 miles it still seems to improve mileage....although less so when towing at higher speeds.

when diesel was 2.20/gal the stanadyne wasn't really a value but now with prices at >than 3$ it is....there is a local shop that sells the 300 gallon/treatment jugs for 24$.

i understand the antijelling/anti fungicide issues with diesel fuel additives and the lubricity issues with very low sulfur fuels and the claims for cleaning injectors, but ....

anyone else increased mileage with an additive?

i duck now under the trailer......

cheers
2air'

i've occasionally tried a tank with some other additives and not recorded any mileage benefit.

[ipso_facto]

A Gear Vendors under/overdrive would work good in your case. I was looking at their products on their website and it sounds like a pretty good system, especially if you've got a 3 spd.

It would. I have the 3-speed tranny. I've been relucant to get it, due to the fact that it's expensive, and given that I drive so rarely, it would take a decade to pay for itself. Secondly, it is a proprietory part, what happens if it breaks down - no easy replacement. Thirdly, it doesn't solve the real problem - automatics are less relaible than manuals for towing. Less heat generated. For me, the real solution is a 5-speed. I realized that after owning autos all my life.

Really, there must be a way to decrease the cruising RPMs, at 60, I am turning almost 3,000 which wastes gas.

[j54mark]

Re: Gear Vendors. I have an uncle who owns a fleet of vehicles, in addition to a used truck dealership. When he buys a new truck for himself (always a 1 ton dually with crew cab) the first stop he makes is at Gear Vendors. I have never been willing to spend that kind of money for one, though.

Re: Additives. With my old Chevy 6.5 turbo diesel the Stanadyne additive gave me roughly a 5% improvement in mileage - from 19 mpg to 20 at highway speeds. I've tried it in my old Mercedes 190, but can see no improvement. I've yet to try an additive on the new Duramax. Somebody will have to sell me on the whys and wherefores of an additive with that motor.

Mark

[Rick56Safari]

This has been touched on in other surveys, but I thought it would be good idea to put all the ideas in one place.
What are you doing, besides the usual things, to improve gas mileage on your TT and have they improved your mpg ?
I am looking at several different aftermarket items: electric radiator fan, new exhaust system and new air intake.

[COLORADO_CAMPER]

Keep clean oil in it, keep the filters clean, keep your tires at recommended pressures and drive the speed limit. Other than that, don't waste your time searching for the "X" that marks the spot of the fabled fuel economy treasure chest. It doesn't exist or every automobile manufacturer in the world would already own a share it.

[Bluto]

I drive a diesel pick up tow vehicle. I have had a couple over the years and noticed that they tend to have a "sweet spot" mph where they seem to run at the best economy and power. Find that and it might help you maintain good fuel economy. For my present truck it is about 60 to 62 mph. The only major mod I have done to my trucks has been to add larger dia. exhaust and flow thru muffler. But, that was mainly to lower EGT's when towing up hills. I didn't see any milage improvement from doing it.

[Inland RV Center, In]

How fast, or slow, as the case may be, somewhat depends on the wind.

How efficient an aircraft flies, is very important on the wind speed and direction.

Installing an "Airspeed indicator" in your tow vehicle, will tell you if you have, so to speak, a tail wind or a head wind.

Obviously, if you have a head wind, it will impede your towing mileage.

When you have an airspeed indicator in your tow vehicle, you simply compare the readings of your speedometer with it.

If your speedometer indicates a speed higher than the airspeed indicator, then you have a "tail wind", which tells you that you can tow faster.

If your speedometer indicates a lower speed than the airspeed indicator, then you have a "head wind", which tells you to drop your towing speed.

What speed to tow at, then becomes a subjective opinion.

Trial and error will quickly tell you what is best for your particular rig.

I personally, increased my towing mileage by using an "airspeed indicator," as a guide, sometimes by as much as 20 percent.

Not bad when you consider todays fuel prices.

We all ignore wind speeds moving on the ground, but every aircraft pilot is acutely aware of wind speed and direction. That's why they usually change altitudes, so as to maximize fuel efficiency, and to minimize time enroute.

Since it works very well for aircraft, it works very well for traveling the highways with a motor vehicle, towing or not.

Try it. You won't like it at first, since it tells you whats going on, and what to do, like it or not.

But, if you really pay attention to it, in short order, "you will love it."

Anything that you can do to increase highway fuel economy these days, really pays dividends.

I know, as I took advantage of that setup, starting in 1970.

Since it worked very well then, it certainly would work equally well, or better, today.

An airspeed indicator can easily be installed. Simply run a 1/4 metal tubing from it, thru the firewall, and forward of the grill at least an inch or two. Fasten the tubing so that it will not easily move when traveling. That acts, if you will, like an aircraft "pitot tube". A static line is not required, since the accuracy of the reading is not as important, as the difference in it's reading compared to the speedometer, which is all important.

Come on pilots, chime in.

Andy

[doorgunner]

Wasn't there another thread about the airspeed install somewhere?
Yup I'm gonna put a ASI on the dash of the burb soon. Got a spare one on the bench.
You know Andy- once I started using a GPS while flying I was all over the sky looking for that favorable wind! It's truly amazing what 100 of altitude will do to improve the fuel burn or should I say speed made good or distance made good. Now I'm getting the nautical, aeronautical terms intertwined. Oh yea that manifold pressure thing too

[COLORADO_CAMPER]

Andy,

I am a pilot and, to be honest, you will have to explain to me how knowing the wind will improve gas mileage on the ground. In the air you have a three dimensional environment to operate within so you can adjust your altitude to find more favorable winds. On the ground you don't have that option so, if you intend to get from point A to point B by the shortest overland route you are pretty well at the mercy of the winds. If the shortest route puts you into an unfavorable wind I suppose you could always choose a different route but then are you really saving anything by increasing your mileage between those two points?

I don't get it.

Personally, I think your attention needs to be focused on the road and the traffic around you when you are driving, not on another gizmo or gadget in addition to the cell phone, GPS and God knows what else people are looking at other than the road.


-Kevin

[AirsDream]

I've got a spare ASI down in the shop in a cabinet, but I don't think I'll install it. Saw a big hole in my new truck's dashboard to house an aircraft instrument that looks out of place? Don't think I'll do that.

I find that what I'm tending to do when towing is to a) "know" where the wind's from ... forecasts and loading up and every rest stop or fuel stop give me a chance to gauge the wind; and b) keep an eye on the TV's MPG readout. Going west is typically into a headwind and heading east is typically a tailwind. If it's a headwind and the wind is significant and the mileage is down, I MAY slow down a bit to compensate for the headwind ... or if I don't slow down, I just grit my teeth and know it'll cost me more next time I stop.

On the other hand, if going with a tailwind, I probably don't speed up just because I can do so more cheaply ... the constabluary take a dim view of that! ("Honest, officer, she just got away from me, what with all that tailwind and all!") Instead, I just smile a little more.

[doorgunner]

It's all about DRAG , aerodynamic waste. Does anyone have any idea about the Reynolds number of their trailer. FWIW airstreams are quite "clean". The rear awning supports in the back of the trailer do a lot to disrupt the laminar airflow and "suction" area created aft of the trailer, VG's need to also be placed on the airconditioning shroud. I'm gonna use the altimeter just for fun. FUN is good!!

[Fyrzowt]

This spring I towed a 29' A/S back to the mid west for a member.
One of the days I had a significant tail wind that enabled me to tow in Drive with tow-haul on. This dropped my RPM and increased my mileage.
While I'm not knocking the wind speed indicator, if you have good awareness of what the wind is doing you can use it to your advantage without spending any more money. Or sawing a hole in your dash.
Next time you're out on the road, pay attention to flags and banners. They give great indicators of both wind direction and speed.
Dave

[Alice&Billis]

I installed a K&N Cold Air Intake that boosted me about 3 MPG around town and even as much as 6 MPG on the highway. That worked until all the "real gas" went away. Now we are on the mixed fuel with "up to 10%" ethenol and so my gas mileage is back down. Now I'm glad I didn't install one of the superchips because you really have to use premium high octane to get any real benefits. Only other modification I would consider is something to the exhaust system, but not certain of what at this time. We will tow our 25er again in July, about 200 miles so I'm curious what kind of MPG we will get towing at highway speeds with the "funny gas." By the way, we tow with our Ford F150 1/2 ton and thats also my commuter vehicle.

[Inland RV Center, In]

Don't have to cut holes in anything.

Attaching the meter on top of the dash with Velcro, works fine.

Then when your running around town, remove the meter and put it back in your garage.

As doorgunner said, it's all about drag. Like it or not, drag has an effect on a car, truck, trailer, and even humans.

Walk against the wind, and you will immediately learn that lesson.

Having towed probably at least 50,000 miles using the airspeed indicator as a guide, more than adequately pointed out, lesson well learned.

Those that express an "opinion" negative to it's use, obviously don't care what mileage their tow vehicle gets, towing or not.

Some people buy an Airstream trailer, because they can tow it at 100 miles per hour, if they wish. Obviously, that person could care less about fuel economy.

In California, the average speed on the freeways is 80 to 85 MPH. Cops don't care because those speeds help the bottle necks. And obviously, being concerned about fuel economy, is not something most California drivers want to talk about, until they reach in their pockets to pay for the next tank of fuel. Hmmmmmm.

Andy

[COLORADO_CAMPER]

Andy,

You still haven't explained how an airspeed indicator helps you save money on fuel. I understand that it may give you a better idea of how the wind is blowing but what exactly do you then change with regard to your driving? If you change your route you add miles so that doesn't seem to be viable. You can only drive so fast to gain any benefit of a tail wind without being unsafe or getting stopped for speeding. You can only drive so slow to minimize the detriment of a head wind without being a traffic hazard or breaking the threshhold of time vs. distance fuel economy. So where's the logic in all this? Or is it just "magic"?

Incidentally, general aviation pilots are more concerned about wind speed and direction for the purposes of heading/course compensation than fuel economy. If you gotta go from here to there and you gotta do it now then there isn't much you can do to compensate for lost economy due to wind. The guys flying the big jets have to think about fuel economy with regard to wind a whole lot more because they only load the fuel necessary for any given flight plus required reserves so they don't have much to spare. They are also under continuous company scrutiny to conserve as much fuel as possible to keep operating expenses down. But, they can also do a lot more with speed, course and altitude alteration to achieve better fuel economy than a guy flying a Cessna (or pulling an Airstream).

-Kevin

[Jim Foster]

I was watching "Mythbusters" a while back. Their topic was wind drag. Now, these guys do some really goofy stuff, but this time they seemed to make sense. They had all kinds of measuring devices. They drove a car at various distances behind a big rig. The closer they got to the big rig, the less energy it took to move the car they were driving. The funny thing was, they didn't have to get right up behind to gain benefit. They got measurable benefit starting at about 50 yards.

I don't like to tow my single axle trailer over 60, but here in California I often find a big rig, usually a UPS big rig, running between 55 and 60. Not the best view, but any gas saved is welcome.

[Inland RV Center, In]

Originally Posted by COLORADO_CAMPER

Andy,

You still haven't explained how an airspeed indicator helps you save money on fuel. I understand that it may give you a better idea of how the wind is blowing but what exactly do you then change with regard to your driving? If you change your route you add miles so that doesn't seem to be viable. You can only drive so fast to gain any benefit of a tail wind without being unsafe or getting stopped for speeding. You can only drive so slow to minimize the detriment of a head wind without being a traffic hazard or breaking the threshhold of time vs. distance fuel economy. So where's the logic in all this? Or is it just "magic"?

Incidentally, general aviation pilots are more concerned about wind speed and direction for the purposes of heading/course compensation than fuel economy. If you gotta go from here to there and you gotta do it now then there isn't much you can do to compensate for lost economy due to wind. The guys flying the big jets have to think about fuel economy with regard to wind a whole lot more because they only load the fuel necessary for any given flight plus required reserves so they don't have much to spare. They are also under continuous company scrutiny to conserve as much fuel as possible to keep operating expenses down. But, they can also do a lot more with speed, course and altitude alteration to achieve better fuel economy than a guy flying a Cessna (or pulling an Airstream).

-Kevin

I am also a private pilot wih over 1200 hours, single engine, with more night time cross country than day time.

Minimizing the effects of drag, is the whole purpose of using the "airspeed indicator."

However, is doesn't really matter what anyone may suggest, as to what to do or how to do whatever, to increase fuel economy, because there will always be someone who wants to be ahead of the traffic, and who also don't care at all, about fuel economy or fuel prices.

My suggestion is solely for those that want to improve fuel economy within reason.

Getting to your destination, as fast as one can, is not the idea, at least to me. When you get there, you get there, but safely, for yourself and others.

If the winds are against you, then just leave earlier, instead of going faster.

Arrival times are always secondary, to safety.

Changing routes of travel tto save on fuel costs, I don't believe is very practical.

Certainly, changing towing speeds because of wind speeds and directions, worked for me.

Quite well, many people that tow, may noy be interested at all, at least not until they see the price of fuel, at there next refueling stop.

Andy

[Bluto]

I notice my mileage suffers when going on and off the highway for fuel stops and rest areas. I'm installing an aux fuel tank to cut down on the number of stops I need to make for fuel. Seem to waste a lot of time too while waiting in line to fuel up.
Rest areas are easy on and off while fuel stations usually are not as close to the hwy.

[2airishuman]

Originally Posted by Rick56Safari

... I thought it would be good idea to put all the ideas in one place...

well that's a great idea and one of the mods TRIED to do just that here...

http://www.airforums.com/forums/f238...ads-18186.html

the info is ALL still current, even as fuel prices have changed.

and new threads on the various issues proliferate, like energy futures and spec u late ors...

often bogus, often vendor driven, often silly and so on...

the new threads on old stuff keep on rolling.

1. going slower is STILL the primary way to extend a gallon of juice...

along with

2.proper tire air pressures and

3. regular vehicle maintenance....

next comes the fuzzy...

4. modulating the rate of acceleration helps too, but this is a challenge base on driver brain and foot...

5. some additives may help, but most of the info is hype to sell stuff

then the stuff that needs an accountants meter...

6. added gadgets (exhaust, air intake, gearing... EVEN IF there are small gains, DON'T usually off set the INITIAL COST for years, if ever.

7. EXTREME mods can really add mpg (aerodynamic changes like lowering, mirrors, wipers, fairings, low drag wheel/tires)

but again are COSTLY to undertake and have done WELL...

or the natural holistic approach...

8. traveling down hill or with a tailwind helps but limits directional options significantly...

and asi on the ground is just another silly gadget, how about just sticking yer head OUT d'window...

followed by the absolutely bogus stuff..

9. and i so ain't gonna give them my air time...

so while the current fuel pricing sparks LOTS of new threads on these issues....

the best stuff is still much of the older stuff which WAS COMBINED to save us ENERGY...

but scatter happens, just like most traffic is 1 person per big arse suv...

searching old threads is STILL free and adds nothing to your carbon foot print...

cheers
2air'