Save fuel
Tips for Improving Performance and Reduced Fuel Consumption (MPG) and Costs for RV's
The overall objectives here are to reduce drag and friction and maximize performance of your power plant and drive line.
First, start with techniques and items that are inexpensive but effective.
Set a goal of how much improved MPG you realistically want to achieve and how much you are willing to spend to get there. There is a cost saving cutoff on the more expensive items that may save gas.
Keep a record of the MPG performance before and after each series or changes made.
The inexpensive but effective techniques are:
VEHICLE CONDITIONING
The jury on high octane gas is still out. Low octane is cheaper, but may affect the life of your valves. I recently talked with a RV’er who had 150,000 miles on their RV, burned the cheapest gas they could find and still were getting good performance from their Chevy 454. I do the same and have not noticed significant difference except for the mountain states where I run high octane. You’ll pay $15-$20 more for high octane for each tank full.
Keep tires at the correct pressure. Manufacturers specify the pressure for the loads you are carrying. Know your weight distribution to each tire. Check the pressure daily on trips, monthly when in storage and only when tires are cool.
If you are in the market for new tires, several major manufacturers now offer a tire specially designed for RV's which is supposed to improve ride, stability and MPG.
Wheel bearings must be properly lubed and torqued to spec to reduce drag. They should be checked at least once a year or to manufacturer’s recommendations.
Drum brakes should be properly adjusted to reduce drag.
Make sure the front end is properly aligned. If not, tires wear quicker and also have resistance against the forward motion of the RV, thus less MPG.
Good shocks, Bilsteins or Koni’s will keep the tires on the road better providing more traction, control and a better ride.
Place a bug screen in front of your radiator. By keeping bugs out the radiator fins remain unrestricted and engine runs cooler, the clutch fan stays off longer result: improved performance. Also, draining and backflushing cooling system annually will help the RV run cooler thus less clutch fan engagement time thus improved performance.
IMPROVE PERSONAL DRIVING HABITS:
Drive at a maximum speed of 55 MPH or as posted, if less. This is probably one of the best ways to improve MPG. Try driving at 65 MPH for one tank full and then at 55 MPH under similar road and load conditions. You'll see a significant improvement in MPG.
Day VS Night Driving: To the extent that nights are cooler and less windy, consider traveling then. Cooler, less wind means less AC needed and less resistance due to winds thus improved MPG.
When on the road look 5-6 vehicles ahead for slower or stopped vehicles or 1/2 block ahead to the next stop light. Start slowing immediately, enough to keep the unit rolling nice and steady. If stopped, start your roll very gradually, don’t floor it.
Don't tailgate. This is dangerous in any vehicle and also a real gas consumer. It wears out brakes, tires, and your patience and uses much more gas. If you must stop or slow down, resume your cruising speed gradually. Re-engage your cruise control AFTER you have resumed top cruising speed. A cruise control engaged too early will try to get the unit back up to speed too fast, decreasing MPG.
Some drivers constantly push and release the gas pedal after reaching cruising speed. Keeping steady pressure, pressing very gradually will improve MPG right away.
Constant lane changing will force you to apply more gas and/or brakes to adjust to the speed of the new lane. Staying in one lane allows for more constant speed, thus improving MPG.
Avoid resting your foot on your brake pedal or clutch pedal when driving. Both habits increase wear on parts and decrease MPG.
Drive with all large windows closed to reduce drag.
ASSESSORIES:
Air conditioning. Run your generator and the overhead coach AC instead of dash air. This keeps the load off the engine, allows it to run cooler and probably overall you will use less gas. Close off all unoccupied parts of the coach with a ceiling to floor curtain.
Using cruise control: be careful here because a cruise control on a RV is efficient only on flat, near flat or down sloping roads. If you are approaching a hill keep the momentum of speed up by overriding the cruise, applying the gas manually before reaching the hill. This will help prevent the unit from lugging down. Manually shift into second gear at about 45 MPH instead of pushing the gas pedal to the floor. You'll improve MPG, your transmission, your engine and your exhaust manifolds.
VEHICLE LOAD:
Water Load: Leaving on a trip with the water tanks full adds a significant amount of unnecessary weight. Fill only the amount of water needed to get to your destination. Then fill the water tanks, if necessary. Drain down before resuming on the trip. Less weight, improved MPG.
Gas load. Run full only if on an extended trip unless in very cold weather. Fill up if the prices at the next stop are significantly higher. On short trips use up as much of the old gas as possible before refilling. This will keep fuel fresher and improve performance. Fill up at or near the final site if you're going to use the generator a lot. Less weight, improved MPG.
Personal items: Take only items necessary for the trip. Less weight, improved MPG.
Now for the POWER PLANT gas savers:
Make sure the RV is running at peak efficiency, tuned up (dyno is best). All ignition components, plug wires, plugs, rotor, cap, coil wire should be in peak operating condition. All vacuum lines should be attached and free of cracks. Plug wires are a chronic cause for poor performance due to the extreme heat they encounter. If your wires are cracked, brittle or over 5 years old replace with premium quality wires only, cost about $40.00. Heat insulation for the wires is available.
Gas Lines: Cracked gas or vacuum lines can cause backfiring and even stop a RV in its tracks. Change all vacuum and rubber gas lines if there are any signs of cracking or a minimum of every 5 years. Use only lines that specify "Fuel Lines" on the hose for fuel and those marked "Emission or Vacuum" for that purpose. A cracked line will not necessarily show leaking but can draw air. This is one of the most overlooked and difficult to analyze problems (along with spark plug wires) on a RV.
Clutch fan: Make sure your clutch fan is not locked when the motor is cold. If it is locked it will reduce fuel efficiency. If it is not engaging at all the unit will overheat. If defective, replace with a factory OEM only, especially on 454's.
Smog Equipment: Should be kept in good operating order and NOT disconnected.
Add-ons/Gadgets/Chemicals:
Window and Vent Coverings: Cover all except windshield and front side windows with heat deflecting tinting or cover them with foil or card stock. Close all unused vents when traveling and make sure they are well insulated. You can purchase an insulating pad that fits the vents. All this improves cooling capacity and improves MPG.
Under the motorhome: On front mount engines completely insulate under the engine cover, called the doghouse. Kits are now on the market or if you wish, buy the insulating material in bulk from a RV repair facility. This will make a tremendous difference in heat transfer and noise reduction.
Miscellaneous: Most RV's have numerous little holes and air leaks particularly in the front. Identify and seal all holes and cracks, silicone sealer or rubberized undercoating works well for this.
Synthetic Oil: The claims are in favor of improved gas mileage but I don't know if the extra cost of synthetic oil gives you a cost offset on gas savings. AMSOIL claims not only improved MPG benefits but greater engine protection and life. Check the manufacturer’s recommendation before putting any additives or synthetics in a generator.
Air Ram: If your unit is carbureated and doesn't have an air ram system into the carb, one can be devised. Make an air scoop by cutting the small end off a 12" funnel. Insert the cut funnel into a 3" or 4" flexible air intake hose and bond it. Attach the scoop to the inside of the grill. Run the 3†or 4†hose upward to prevent rain influx, into the neck of the air cleaner. The unit now takes in much cooler air and it is being forced rather than sucked into the carb, somewhat similar to a supercharger. Make sure the rest of the air cleaner is sealed to capture all the air being forced in. Total cost about $20. Get ready for improved performance.
AIR Filter: Changing to a less restrictive air filter, i.e. K&N will result in a pay back. They claim less airflow resistance with improved air cleaning. Guaranteed for 1,000,000 miles, Do a before and after test on MPG. Costs about $35.00.
Attaching a Magnet on oil filter will capture metal filings, reducing wear, improving life and performance of engine. Available at any hardware store, costs $2-$3 for a strong one.
Outside Resistance Reduction:
Air Dams: Rear Air Dams are available for Class C motorhomes, A roof air dam in the rear offers reduced drag and a cleaner rear end. I don't know why the class A manufacturers don't offer them.
Ever notice most semi's have a rounded front and air dams on them? Why? For improved MPG. I think someone should offer air dams for RV's, as I believe they would help improve mileage by reducing drag.
Now for the more expensive add-on items:
The Banks Performance add-on system claims more HP but I’m not sure about about MPG gain. I would look at installing free flow headers (stainless if you can afford them) and exhaust 1st. OEM exhaust systems usually restrict outflow thus performance.
Headers: Custom, high quality, low resistance headers and exhaust systems may improve mileage, for sure an improved power curve. Cost about $500. Unless you need added power, I would question if you will see a positive return in your investment. Depends on how long you plan to keep your unit and the number of miles you will be driving times gas mileage improvement minus cost of headers.
Add on gear to transmission: Principal is to add gears between the stock gear ranges to keep Rpm's up and improve power curve in climbing. Also can provide an overdrive gear range for cruising range thus same runrate (MPH) with less engine Rpm's. Major vendor is Gear Vendors, El Cajon, Calif. Costs somewhere in $2-$3K range depending on your unit. They have a website.
Fuel Savings:
Join a super discount chain i.e. Costco, will usually have lower prices than major suppliers.
Fill up now if you anticipate prices are going to continue to rise.
Fill up in early morning or late evening, cooler and less crowded.
Check internet for best prices in your area, gaspricewatch.com.
Limit your camping to local areas.
Plan long trips to states with cheaper gas.
Drive less, reallocate your gas allowance by carpooling or public transportation to work, then apply the saving to fun in the RV.
I hope this information helps you achieve improved performance and MPG and to be able to enjoy you RV even in these times of high gas prices.
Just remember, if you’re getting 7MPG now as many do and you can get your unit up to 8 MPG average, that represents a 14% or 32 cents per gallon savings @ $2.25/gal.
I welcome your comments/suggestions.
Happy RV'ing!
Best Regards,
Russ Ritenour
Russ748@adelphia.net
951-699-6731
Additional Resources:
http://www.fmcanw.org/fueleconomy.htm
I pull over and let 'em pass.....