exercising the ICE?

Good question , all i know is as written in the manual , the car will warn you te re-fuel/add fuel if the gas in the tank become too old .. something like 10-12 months ... but no info about the ICE itself.

 

my ng generator with honda engine also recommends that. but auto manufacturers have come up with sophisticated technology to eliminate that need.
my 2012 pip runs the ice every 124 miles. the prime, 5 years later, no longer needs to do this.
no worries, toyota's gotcher back!

 

The owner's manual mentions it'll run the ICE periodically when it needs. It'll also warn you if the fuel is getting stale. When I bought mine I put it in HV Mode (even when not needed) and also enforced charge mode while sitting (see manual) once just to make sure my engine worked! It seems like the engineers programmed it to take care of the engine, but also strive to not use it. It'll probably be okay to wait until your first trip out of town. I've read to not use fuel stabilizer. Also, maybe only put a minimal amount of fuel in and add periodically to keep it fresh if you don't use it much.

 

does mixing new gas with old solve the 'going stale' problem?

 

why? is that what you do?

 

It'll help. Part of the going stale issue is lighter weight molecules evaporating off. Adding fresh replenishes them.
But the real reason PHEV owners do this is to reset the timer for fuel maintenance, and keep the ICE from coming on. Takes 3 gallons to do so in the Volt.

I would not worry about the fuel going bad. Car fuel tanks are far better sealed than whatever you keep the gas for your lawnmower in. That will keep it fresh for longer.
As for lubrication of the engine, the M/G1 can spin the ICE up over 1000rpm for start up, and it would be easy for Toyota have it just spin up for circulating oil if they felt the need for it.

 

Why? And where did you read this? I didn't see any red flags about it in the manual.

As far as I'm concerned, I won't bother with running the engine except for a longer trip tomorrow or when it gets really cold out.

 

the pip manual says to add gas every 6 months. or not to let the gas sit in the tank for longer than that, or something, i forget exactly. so i use all the gas down to the blinking bar by 6 months and refill. but that's only 8 gallons, and there are 2 gallons of old gas left in there.

korey said in post #4, it will warn you when the fuel is getting stale. so, do you add fresh fuel, or siphon out the stale?

 

yup, start sucking @Bisco

 

From the owner's manual (pg 96)

• For plug-in hybrid vehicles, fuel may remain in the tank for a long time and undergo changes in quality depending on the how the vehicle is used. Refuel at least 5.3 gal.(20 L, 4.4 Imp.gal.) of fuel every 12 months (refuel a total of at least 5.3 gal. [20 L, 4.4 Imp.gal.] over a 12-month period), as this may affect components of the fuel system or the gasoline engine.
• If the vehicle has not been refueled for a certain amount of time and it is possible that the quality of the fuel remaining in the tank has changed, “No new fuel has been added recently. Please refuel” is displayed on the multiinformation display when the power switch is turned to ON mode. If the message is displayed, refuel the vehicle immediately.

As a fellow engineer and an advocate for Toyota's quality/reliability, I trust the Toyota engineers' guidance in the owner's manual. I doubt they pulled those numbers out of their...imagination. A modern car is different than small lawnmower engines. They are generally well-sealed and probably less prone to issue due to larger parts and computer-controlled operation. The problem for gasoline is that being exposed to air allows it to oxidize and also the volatile compounds can escape, as others mentioned. Because it is well-sealed, sitting fuel will last longer in the car than in lawnmower engines. Also, it'd be best to keep it near full to minimize air space. Toyota's statement recommends adding new fuel to old, which corroborates my earlier statement; this is likely helpful not in that it revives or fixes the old fuel, but, rather, the solution is dilution and the mixture of new fuel with the old will bring the mixture's combustion characteristics within recommended limits for proper operation. [I used to run a bi-fuel vehicle (filtered waste vegetable oil and diesel). If running on VO and the engine started to run rough (perhaps a bad slug of VO), I added a "spritz" button to quickly inject pure diesel and it would immediately fix the issue due to the improved mixture. Interestingly, sometimes the VO quality needed to run an engine was higher than that needed to fry our food ]

I will clarify my earlier statement about fuel stabilizer: I doubt that fuel stabilizer would do harm (if used according to its directions), but I think it is unnecessary. It'd be better for the engine (IMHO) to run it every month or two as opposed to adding fuel stabilizer and letting it sit unused. If I haven't used the engine in a month, I'll probably put it in HV Mode for a day. If someone is really going 12 months without using a half a tank, they should have probably purchased an EV and rented a car for the biennial cross-country trip.

 

For my daily trips the ICE comes on minimally, depending on many factors. I don’t concern myself with it, it’s normal. If your driving only uses the EV mode then run it in HV once in a while. MPG is still phenomenal! That’s the goal, right?