So I just got my prime, and because of the pandemic and working from home for the foreseeable future, I was wondering how much of a difference if i don't keep a full tank of gas vs keeping maybe keeping only 1/3 or 1/4 of a tank since I'm mainly driving locally and charging up the battery. I would think the added extra 8 gallons of weight would affect the gas mileage a little bit but over time would add up to at least something more substantial.
Do whatever pleases you. Any difference is tiny and insignificant. It is important to not let the gas in the tank "go stale". Your owners manual should tell you how much and how often you need to add fresh gas.
If your daily drives are mostly within the EV range, then keeping the half-tank or even a quarter tank of gas would be fine. You are not going to see discernible differences in the gas mileage, but you won't have to forcefully burn the gas to just refresh the "stale gas" as much. The gas going to stale is another hot topic, and some believed it is not going to affect much, but Toyota recommends filling at least a half tank of fresh gas every 12 mo.
The proper amount helps. The key word is "helps". There is no guarantee. IF you are still under warranty, you should follow the recommendation in the manual. Adding the recommended amount of a fuel stabilizer is a good idea too. "A few ounces" is not a good recommendation. Read the directions.
The only possible drawback to filling the tank halfway that I can think of would be that it makes it hard to track your fuel economy with an app or a spreadsheet.
Ok thanks for the replies I had a 2010 prius and gotten to the point of too lazy to keep tracking fuel economy. But yea i think i'll just keep maybe 1/3 of a tank and that way can add a few ounces of fresh gas i dont let it go stale.
"A few ounces" is not enough. If you start at 1/3 full, you should add at least that much, bringing it up to 2/3 or more.
Six -vs- Half a dozen for most people. However (comma!) If I owned a dual-fuel vehicle I'd maximize the capacity of BOTH fuels, but then I live where Hurricanes and tornadoes can impact electrical service and access to gasoline. I've also lived in places where fires, flooding, snow, ice, even civil unrest can interrupt one's access to gas temporarily. With the exception of my work car, or a personal car when I'm on a road trip, I usually try to keep my tank FULL rather than empty. YMMV....
... or skip the Stabil, just follow the guidance in the Owner's Manual and be good for a full 12 months.
That is a HUGE assumption. Mainly assuming that the gas you are using is in "pristine" condition when it comes out of the pump. Sometimes it is NOT.
And Stabil is going to fix that? For people buying fuel from a remote low traffic station storing fuel in old style five gallon jerry cans, you have a point. For those buying from high volume stations with underground tanks getting several tanker loads of refills per day, this is much ado about nothing.
Maybe. But it can't hurt......if done right. For people buying "premium" gas in an area without may cars that actually require it......that your car doesn't need......the gas in that tank might be a LOT older than your example would indicate.
The gasoline stabilizer additives do work. I keep about 10 gallons of gasoline in 3 gas cans for my power tools and some often sits almost a full year before it is used (unless there is a power failure). I put Stabil in each can when it is filled and have never had a problem with stale gas. JeffD
None of those have PHEV-style sealed tanks, which are intended to keep the fuel good for 12 months without stabilizers. I've seen no evidence brought to this forum that they fail in that goal. So, from that perspective, claiming that a particular stabilizer will keep the fuel in a sealed PHEV tank for "almost a full year" falls into the category of "damned by faint praise". Indistinguishable from a placebo. For sealed tank PHEVs, stabilizer proponents ought to be looking for and highlighting benefits well beyond a year. Otherwise, it stays in placebo territory. Time for a rerun rerun rerun rerun rerun: How desiging the Chevy Volt's sealed gas tank brought automakers, CARB together "... but now we've got the scoop on the gas tank used to keep liquid fuel in the Volt from evaporating or going stale for up to a year. " Just like usual, you do it then complain about anyone else who follows up.
I'm inclined to agree, Fuzzy. I buy the cheapo gas. I don't use Stable, but do toss in some Techron every couple years or so. My gas has been in the tank now for 5-1/2 months so far. I'm down to 3/8 of a tank. I still get mostly 70 mpg driving in HV mode.
And just like usual, YOU cannot seem to have an adult discussion without being nasty and insulting about it. Evaporation is not the ONLY factor that makes gas go "stale". Other factors, like it's initial purity likely are even more important.
