FR3 25DS MPG; W/Prem Octane

[dloy1324]

Hello All,

Curious as to what kind of MPG 25DS owners are finding without pulling a toad.

Also has anyone experimented with using mid-grade or higher octane gas and how it effects MPG.

Thank you for your comments

[StephanFR3]

No, but that would just waste money. Computer controlled engines don't ping unless they are in need of maintenance. Or have been modified. Just remember if you modify you will find the weak link. My buddy's ford diesel blew his head gasket by running a chip. 2k to 3k to fix.

[SEGV]

I've read - on one of the RV-related forums - that the low end gas (85/7-ish octane) is more appropriate for these engines. Apparently, its what they're designed for, running higher octane was (memory is fuzzy here) bad for the engine? Not beneficial enough the justify the expense? something like that.

[dloy1324]

Thanks for the info. I hadn't thought that it might be harmful for the engine. Good to know...thanks

[StephanFR3]

It's not going to hurt, but is just a waist. The motor requires 87.

[waiter21]

I average right at 8.2 mpg, running 60-65 mph pulling a 2001 Civic.

I've never used premium in the MH as its not required.

[jogalot]

Just returned from a 6500 mile trip from Florida to mid western states. With all the flat, climbing up an down the rockies we Avg. 9.3 for the entire trip. Coach ran excellent. Had no problems climbing up all the steep grades, plenty of horsepower. We did not have a toad so I am sure that help. Just the Mrs an I on the trip so there wasnt a lot of weight either. I ran just reg. fuel of all different brands. Paid a low of 2.24 an a high of 3.59 throughout the entire trip . Ours is a 2015 FR25 now with 8100 miles, bought from camping world in the second week of June. Hope this helps a little.

[johntaylor]

Higher octane fuel will have no effect on mpg, and it will not harm the engine. It is intended for high compression engines, to prevent pre-ignition (pinging). Using it in an engine that does not require it is simply a waste of money. The oil companies call it "premium" to fool customers into thinking it's a better product, and they set the price high to reap the benefits from those who fall for it.

[PetenJeanne]

johntaylor, have you ever tried conventional gas? By that I mean gasoline that has NO ethanol in it. I've run it in my personal vehicle and have noticed a 3mpg boost, but the one station that sells congas is VERY RV unfriendly(hard in and out). First chance I get to give it a shot I'll let you guys know how it works. Till then, see ya around the campfire.

[StephanFR3]

That is what I run in my lawn equipment, but it is not sold a conventional gas station but at a oil supply company that does fleet sales and bulk fuel delivery. It is also 90 octane and about a dollar more per gallon. Possibly "albeit long" make sense for fuel for winter storage, but not for normal use.

[PetenJeanne]

Just outside of New Orleans there are several places that sell conventional gas. I gripe because the one closest to my home is a hard in and hard out even for a 26footer. I work part time at a Sam's station and mixed regular was $2.04 a gal. Cash price at closest home conventional store is $2.39 a gal. Don't think I would use it at a buck more a gallon either. I don't know if it's all in my head but the Lexington seems to run better on it and mpg is closer to 9.5 than 7.5 ..is it worth the extra $.35 a gal? Go figure. Happy trails and we'll see you around the campfire one day.

[StephanFR3]

At that price difference I would certainly use the non ethanol fuel. Especially as much as rv's sit without running.

[johntaylor]

Originally Posted by PetenJeanne

johntaylor, have you ever tried conventional gas? By that I mean gasoline that has NO ethanol in it. I've run it in my personal vehicle and have noticed a 3mpg boost ...

Ethanol produces less heat energy per gallon than gasoline, so you should get more mpg without it. There's an interesting chart here that says E10 has 96.7% of the energy of gasoline, and info here where the govt admits that mpg suffers by up to 5%. Automakers say ethanol harms your engine, and it causes problems in the economy and the world food supply.