Noticed Massive MPG drop when accelerating

I think you're being paranoid. if your average drops, then you have a problem. make sure your tires are fully inflated to keep the mpg up. most folks run 40psi.

 

What do the voices tell you?

Just kidding.
I wouldn't worry about it unless you start to see a significant TANK TO TANK loss of gas mileage.

My observation is that upon initial, immediate, fully warmed up engine starts with decent battery charge, the MPG's will be pegged as the vehicle starts out on electric propulsion if possible. Usually this doesn't last but a mere second or two, if you need torque to reach whatever speed. And the mileage will plummet until you get the speed you want and gain some momentum.

But I wouldn't really pay so close attention to what the gauge is saying on something as precise and short lived as starts and stops.

Figure your MPG on a tank to tank basis, and over a period of several tank fulls. That will be a much better indicator of how your Prius is doing from a MPG standpoint.

 

Accelerating takes a lot of energy, thus burns a lot more gas than cruising on a flat surface. If you're not getting below 25MPG instant, the person behind you probably wants to kill you.

Most people find accelerating more on the quick side actually results in better MPGs (of course don't do this when you're going to have to stop again right after getting to speed). Your current MPG is going to be bad when accelerating, so why not make it a little worse but decrease the time you're accelerating. I find that accelerating about as fast as the rest of traffic gets good results.

 

I wouldn't worry too much about the instantaneous MPG, but I would be concerned if the battery SOC is permanently low. Just because you haven't driven much in the last few days shouldn't make your (traction) battery low, and even if it did then (once the engine is warm) the traction battery should return to normal charge levels in 5 minutes or so.

Perhaps this is the problem. If you drive too light footed then the battery will tend to drain more than it charges (well for a little while anyway), and you'll end up with a low state of charge and the crappy performance that you seem to be getting.

Yes it does. The Prius can feel somewhat underpowered, and the engine seem to work excessively hard when the state of charge is low. Man up and stop driving it like your grandma.

Well at least until you've gotten used to it a bit more, then you can drive like a grandma under controlled conditions and call it "hypermiling". But when you learn to hypermile one of the first thing you need to learn is how to do so without draining the battery.

 

I accelerate briskly from stops. I'm usually faster than surrounding traffic up to the speed limit. Then I go for best gas mileage.
I average 44 to 50 depending on the season. Don't worry about startup MPG.

 

You are observing basic physics of fuel consumption on you computer screen. "An object at rest tends to stay at rest ..." It takes a hellluvalot of energy to move a 2 ton box of metal from zero to 30, to 41, to 55 ... "An object in motion tends to stay in motion" is the glide part of "pulse and glide" and is the secret of hypermiling.

 

TheWiredWorld - To answer your original question, I can verify that my screen indicates single digit mpg very often during acceleration. It all works out in the end. As others have indicated, your instant mpg is not something to agonize about.

As long as your overall average at the end of the tank fairly matches the driving conditions for that tank don't worry about it.

 

One more thing: your battery SHOULD be in the middle of the graphic, not at the top. It's the way the Prius was designed.