Tom in Tulsa wrote:
,,, Questions: 1. Do fuel additives work and which ones do and don't. Fillups are around 50 gallons on a 75 gal tank.
2. Is going to 100% gas (no ethanol) cost effective?.
3. My Class A is 2008 (11 years old) with 53,000 miles. Is it time for a tune up and what gets tuned up? Spark plugs, injectors, wires?
I am not a mechanic and am only guessing.
What works and what doesn't? ,,,
1. For the purposes of increase fuel economy fuel additives do not work. If one did every gas RV owner would be buying it in by the pallet load.
2. Cost effective? No. 100% gasoline fuel does have a higher percentage of BTUs and may increase mileage slightly but it is unlikely you will see enough of an increase to make up for the higher cost of the fuel.
3. The plugs are good for 100,000 miles. Coil packs (replaced the plug wires) area replace on failure item. You could try an injector or "top end" cleaning service but if the coach is performing adequately at speed then do nothing.
What works to help with mileage?. Pretty much nothing you can buy. Best practices will help the most. Stay on top of routine maintenance and inspections. Keep your load and associated coach weight as low as possible. Watch your speed and go easy on acceleration from a stop.
Consider a Scan Gauge which you can use to monitor instant and average fuel usage to help lighten your right foot. When you see an instantaneous usage of 1.2 MPG it has a way of getting you to back off the throttle.