List of ways to improve fuel economy?

[skyisblue]

Hi all,

I drive a 2005 Prius that I bought used last year with 60,000 miles on it. Throughout this last year I have never had a tank of gas that got more than 45mpg on average (generally my average is 39). Since it has been a year without change I thought I should make sure I am not missing any ways of improving it.

I live in Berkeley, CA and generally make two sorts of trips. First, the short "around town" trips which are not more than a few miles. Secondly, I take it on longer weekend surf trips to the beach. I have a roof-rack on my car at all times and sometimes transport boards on top (and expect those trips to be lower on fuel economy), but if it is just me I tuck my longboard inside to save on fuel. I know that the roof rack is going to cut the fuel economy some, but it can't be a full 10mpg. Even on a tank of gas where I do not carry my board at all, I don't get more than 40mpg.

I try to keep my tires pumped up to the higher psi, I change my oil every 5,000 miles, I practice pulse and glide as much as possible and am not a lead foot in town but do drive your average 70 mpg on the CA freeways.
Is there some other maintenance I should be doing? What am I missing?

Thanks!

[dwdean]

Originally Posted by skyisblue

Hi all,

I drive a 2005 Prius that I bought used last year with 60,000 miles on it. Throughout this last year I have never had a tank of gas that got more than 45mpg on average (generally my average is 39). Since it has been a year without change I thought I should make sure I am not missing any ways of improving it.

I live in Berkeley, CA and generally make two sorts of trips. First, the short "around town" trips which are not more than a few miles. Secondly, I take it on longer weekend surf trips to the beach. I have a roof-rack on my car at all times and sometimes transport boards on top (and expect those trips to be lower on fuel economy), but if it is just me I tuck my longboard inside to save on fuel. I know that the roof rack is going to cut the fuel economy some, but it can't be a full 10mpg. Even on a tank of gas where I do not carry my board at all, I don't get more than 40mpg.

I try to keep my tires pumped up to the higher psi, I change my oil every 5,000 miles, I practice pulse and glide as much as possible and am not a lead foot in town but do drive your average 70 mpg on the CA freeways.
Is there some other maintenance I should be doing? What am I missing?

Thanks!

Hi there,

My parents still live in Berkeley and have a '04 Prius (no roof rack). They average in the mid 40's. My dad says he doesn't so anything "special" in the way of driving, except for having a lighter foot.

Just remember that short trips are FE killers. Can you "batch" errands, going to the place that's the most distant first and then working back to your residence?

The other thing you can do is look at your routes. For instance, my parents will drive down the steep part of Marin in the Prius, but they always go back up the hill on streets with more gentle grades. I know that may be a bit an extreme example, but it should certainly illustrate the point.

I don't really think that you're going to find a mechanical answer to this, but you might find answers in looking at how you're driving.

[skyisblue]

Yeah, thanks, dwdean, I have been trying to do that. I do combine my errands when possible (and do as many as I can on foot or on my bike) and I live in the flats of Berkeley so I don't have the hills issue.

I also drive differently in the Prius than in my old car, no "jack-rabbit" starts, I have learned to anticipate light changes, etc.

However, I still feel deep envy for the 50mpg+ folks!! Maybe 40 is just going to be my reality, but I wanted to make sure I shouldn't have anything else checked out or that there wasn't some driving tip I was missing.

[richard schumacher]

How fast do you go on the beach trips? The roof rack may be hurting even more than you think.

Do you ever shift into "B"?

[F8L]

It takes some time to get used to but eventually you figure it out. Getting better MPG that is.

I was stuck in the mid-high 40s for a very long time. I even complained about how I could not get better milage even though I tried P&G and other little tricks. Eventually I started to master the throttle control and now I can get 60mpg tanks if I alter my route and try hard to max mpg. If I don't try hard, use normal routes and drive the speed limit I end up with 49-53mpg. So there may be hope for you unless you just have a terrible route.

One thing i notice myself doing that the average drive may not do is to accelerate up to the posted speed limit fairly briskly then let off the pedal fully then reapply lighter pressure. Now I realize most PriusChat people do this but your average Joe probably does not. Once you realize the difference this makes you start noticing other instances where lifting off the throttle then reapplying pedal can change your instant mpg by 10-20mpg quickly. In this instance you are simply changing the amount of time you sit at say 23mpg before you transition to say 50mpg. I see this alot on city streets where the speed limit is around 40mph and if you accelerate like a normal car and do not do the "throttle lift/reapply" trick the MFD will sit right around 40mpg or so and slowly raise up to 50+mpg (like it should be at 40mph). Maybe this doesn't play as large a part in efficiency as i think it does but it surely cannot hurt.

Gliding whenever possible is the largest producer of big numbers for me. I can drive like the average Joe most of the time but if I throw in a bunch of nice long glides my MPG shoots right up.

[Mr.Vanvandenburg]

I live in the bay area. My tank avgs are 51-52. My tires are 35/33, I don't like the harsher ride. I usually have the MFD off, but use the graph screen to check totals at times. I do better with feel. Back off as much as possible on the gas pedal, like there is an egg under the foot. Slow down to 62 or less on the freeway. Back off the gas at 60-62 and the engine really goes low in rpm, silent it seems. I get 52-54 on level freeways at that speed. I disagree with others about brisk acceleration. I have tried it that way on the same course, and it uses more fuel. The owners manual also tells to accelerate gently. Drive like the little old lady from Pasadena. The gas pedal is very very sensitive on the Prius. Check the engine air filter and make sure it is not clogged. Driving in traffic 30-35 mph, I am seeing higher mpgs. At 50 mph with lots of stoplights and accelerations I see the lowest mpgs about 50 or just under. Moderately brake as much and long as possible, not just coast, when coming to a stop. Just hard enough not to annoy the SUV three feet behind. That roof rack may be some of the answer. My 51-52 avg includes lots of cold start, short trips, driveway moving where the engine starts for nothing, and the like. I rarely drive more than 6 miles per restart. That's my list.

[Codyroo]

1) Slow down on the freeway. Try not to exceed 65 mph, 60 mph is even better. You won't save that much time driving 70 mph vs 60 mph.

2) If you can, take off the roof rack for a tank or 2. (reset your mileage) and see if you note a difference. I don't know how easy it is or is not to remove and put back your roof rack, but try it if you have the time and the effort isn't too great.

[darelldd]

My best advice is to not concentrate on miles per gallon, but concentrate totally on *gallons*.

What's better:
1. Getting 50 mpg during a month of driving, and using 10 gallons (500 miles of driving) for that month...
or
2. Getting 40 mpg during a month of driving, and using 5 gallons (200 miles of driving) for that month?

When we concentrate on the mpg, we sell ourselves short. We should be bragging about how much we didn't drive. About how much gas we didn't burn. Instead, the emphasis is on mpg - and for many, that means driving MORE miles, and burning MORE gas so that number looks better.

Might not be the case with you... but if you just concentrate on NOT driving the car so much, it really doesn't matter what your mileage is when you DO drive it. For the short trips around town - ride your bike. I managed to live in Berkeley for several years without even owning a car. I even had a girlfriend way up in the North hills!

[F8L]

Originally Posted by darelldd

My best advice is to not concentrate on miles per gallon, but concentrate totally on *gallons*.

What's better:
1. Getting 50 mpg during a month of driving, and using 10 gallons (500 miles of driving) for that month...
or
2. Getting 40 mpg during a month of driving, and using 5 gallons (200 miles of driving) for that month?

When we concentrate on the mpg, we sell ourselves short. We should be bragging about how much we didn't drive. About how much gas we didn't burn. Instead, the emphasis is on mpg - and for many, that means driving MORE miles, and burning MORE gas so that number looks better.

The best advice yet!

[dwdean]

Originally Posted by skyisblue

Yeah, thanks, dwdean, I have been trying to do that. I do combine my errands when possible (and do as many as I can on foot or on my bike) and I live in the flats of Berkeley so I don't have the hills issue.

I also drive differently in the Prius than in my old car, no "jack-rabbit" starts, I have learned to anticipate light changes, etc.

However, I still feel deep envy for the 50mpg+ folks!! Maybe 40 is just going to be my reality, but I wanted to make sure I shouldn't have anything else checked out or that there wasn't some driving tip I was missing.

You're welcome. Believe me, I understand the envy thing, my parents even express that.

I think that some of the differences are terrain and other driving conditions. I know that west Berkeley doesn't have any extreme hills, but I promise you, you've got more terrain that we do here. I also know that I'm learning to see the very gentle terrain that we've got and make appropriate gas peddle adjustments.

Even driving here, it's very easy to give the Prius more peddle than is actually necessary to maintain a desired speed. That's another FE killer because gas is being burned to no effect other than spinning the ICE. It's one of the reasons that I've seriously considered buying a Scangauge. For whatever reason, I'm not picking up on clues from the car about what's happening, with all my previous cars it was easy to hear the engine and feel what was going on because of the transmission.

With the Prius, I find locating those clues rather harder (especially with the radio and AC going.) I haven't gone to the extreme of turning the radio off and won't be turning the AC off this summer (average daytime temps in the high 80's to mid 90's.)

The other thing to keep in mind is that with your averages in the 40's you're still doing a whole heck of a lot better than most cars are.