Is it Me or the Car?

[DoriJ]

2010 Prius II

I'm beginning to wonder. I have NEVER (since July) gotten more than 46 MPG., usually around 43. True, it's almost all neighborhood mileage (stoplights, speed bumps, stop signs), but I am driving as consistently as I can. Cars are passing me at 35mph, as I glide away from stops. Any of you experience the same? Or any advice from you high mileage people?

[Jayhawker]

One noticeable improvement you will definitely see is if you inflate the tires up to at least 40 psi.

[Rae Vynn]

Don't "glide" away from stops.
That's one of the classic blunders...
Instead, rapidly accelerate up to speed, then ease off. Not TOO rapidly (i.e., don't floor it), but do think about quickly getting up to speed. Very short accelerations, coupled with easing off and then gliding will improve your MPG.

[a64pilot]

I disagree. Moderate acceleration rate is acceptable, up to say 75% of the mid portion of the HSI, but anything more is counterproductive. It's Physics pure and simple and there are no "magic" portions of the engine power band that are much more efficient than any other, any more than there are certain speeds that will yield better fuel economy than others.
If you look at Bob's mileage graph, it's pretty straight.
I have found that if your really after mileage above all else accelerating very slowly will result in better mileage, but a more brisk rate of acceleration is a lot more acceptable to other traffic and doesn't hurt mileage very badly, unless the type of driving your doing requires constant decel and accels.

[wfolta]

I agree with the faster acceleration. Before the 2010's and their HSI, someone had brilliantly come up with a rule-of-thumb for acceleration that works well: accelerate so you're getting 1/2 your MPH in MPG. So basically, you should have roughly 1/10 as many MPG pips as your current speed: 1 at 10, 2 at 20, etc. Also, there's always a point where you can ease off of your acceleration and still stay ahead, which for me is around 40 or so, I think.

This pretty much amounts to driving in the right 3/4 of the HSI. I really don't use the HSI anymore, since the MPG gauge pretty much tells you everything that the HSI can.

(I think the 1/2 MPH rule was perhaps for the pulse phase of P&G, but it works reasonably well for me for overall acceleration.)

Perhaps slower acceleration that this is the absolute, most efficient, but I think that most newbies make the mistake of accelerating way too slow, which annoys other drivers and really doesn't help on the mileage front.

HARD acceleration can kill your mileage, for sure, but moderate-strong acceleration coupled with looking ahead and driving smoothly is the key to sustained mileage and concentrating on embarrassingly slow take-offs is counter-productive.

[Felt]

There is good advise above, but you are a victim of the driving environment. Remember, the EPA conducts their test in am almost sterile environment, and tries to simulate real-world circumstances. The Prius is capable of much higher mileage ... but under the best of driving environments.

Next weekend fill the tank; press reset; drive out over to Annapolis. Cruise the back roads and drive between 45-55 mph. Drive as steady as possible, coasting on downhills; fill the tank again and calculate the mileage. I assure you your Prius will better the EPA figure.

It is a remarkable vehicle, and certainly capable of the performance promised. On the other hand, think of how much gas all the other motorist are using driving in that environment you decribe.

[alfon]

There are many factors that have a effect on MPG's. The BTU (energy content) of a gallon of gasoline. Gasoline with 10% Ethanol will have a 5-10% drop in BTU's which will effect your MPG's.

Short trips in cold weather will drop your MPG like a rock.

Road conditions, smooth paved level roads, will have a positive effect while wet roads will have a negative effect on mpg's.

Tires should be inflated, mine are at max sidewall pressure in all 4 at 44 PSI, Michelin Energy Saver tires.

The last and most important is driving habits. When my wife drives our car she will average 46-49 MPG. When I drive it is usually in the mid 50's.

Alfon

[Dark_matter_doesn't]

Based on experience, moving off briskly from a stop, even going into the Power zone for a few seconds, yields the better MPG overall. Also, learn to let up on the gas pedal and depress it again when moving, almost like you were shifting a manual transmission. This can cause the vehicle to shift modes and give you better efficiency. Use the MSI as a guide.

Try running in Power mode as well.

[DoriJ]

Originally Posted by Rae Vynn

Don't "glide" away from stops.
That's one of the classic blunders...
Instead, rapidly accelerate up to speed, then ease off. Not TOO rapidly (i.e., don't floor it), but do think about quickly getting up to speed. Very short accelerations, coupled with easing off and then gliding will improve your MPG.

No kidding? I'll have to try that. Thanks.

[DoriJ]

Originally Posted by Felt

There is good advise above, but you are a victim of the driving environment. Remember, the EPA conducts their test in am almost sterile environment, and tries to simulate real-world circumstances. The Prius is capable of much higher mileage ... but under the best of driving environments.

Next weekend fill the tank; press reset; drive out over to Annapolis. Cruise the back roads and drive between 45-55 mph. Drive as steady as possible, coasting on downhills; fill the tank again and calculate the mileage. I assure you your Prius will better the EPA figure.

It is a remarkable vehicle, and certainly capable of the performance promised. On the other hand, think of how much gas all the other motorist are using driving in that environment you decribe.

This weekend I drove to a vineyard in the country, I was on twisty country roads &, for the first time, my Goldie showed 50.5 on the MPG display for about 40 minutes! So I think you're absolutely right,
Thanks.