Short Trip Myth

/Facepalm

So we now have 5 pages for.... nothing =)

 

Although my daily commute is very short, I have long drives in the weekends and holidays. For the 4th of July, I drove 1,111 miles to Canada on a 4 days road trip. I used about 18 gallons. A Matrix might have used about 35 gallons (@32 MPG highway) on the same trip. Friends/relatives with two minivans went along. Quest got about 20 MPG and Odyssey got about 27 MPG.

Overall, I drive about 11k miles per year. That's about average, I think.

Matrix doing 2 to 4 miles short trip will not get it's rated 25 MPG city. Maybe 20 MPG for half of my miles and 32 MPG for the other longer trips. So the average may be 26 MPG. At annual 11k miles, I'll use 423 gallons. I am getting about 94 MPG with PiP so, for 11k miles, PiP would use 117 gallons (and electricity).

 

have to agree, I considered nothing under $25, 000

 

I'm obviously wasting my time here, but PIP is not for everyone. Too short range for me. My next car is going to be Volt or Leaf, or Tesla. Not decided yet.

I didn't buy Prius to be green or to save money. If that was my primary objective, I would keep driving my 10 year old corolla, duh!

How hard is to understand that?

 

Here's one reason I'm having a hard time understanding the "short trip" problem. I know what happens when I drive for about 10 minutes with A/C in my Prius, over the local roads and hills--I get 38-42 MPG or so, 5-9 MPG less than I get on longer highway trips (about 47).
But I DON'T know what I got on a short trip in my prior car--like Jacek's, a 10 year old Corolla--all I know is I got 30-33 or so overall. I don't know what other cars get on short trips, either absolutely, or as a percentage of their overall mpg.
Anyone here figured that out for his/her non-hybrid car(s)?

 

Non-hybrids usually dont come with MPG display. For short trips, Prius still double MPG of a comparable non-hybrid.

 

Some come with a tachometer, which clearly shows RPM is higher during the first few minutes of driving. They too have a warm-up penalty.

 

"How hard is that to understand" you mean? Leaving out a word or two can make it very hard to understand =)

Sorry, had to. Carry on, let the battery wars continue. I never in my life thought I'd see the day where guys were arguing about who's battery was bigger, and who had more range...... Makes for a good chuckle though.

 

To save you guys some trouble, "Dan Cathy", better known as "prius_in_pa", uses different user names. He used the "prius_in_pa" name on the PiP boards for about 2-3 weeks starting at the end of last month, derailing threads, spreading and repeating false information, and using abusive language/profanity...His account disappeared in the middle of this month after he violated the terms of use of this site. It's not hard to see, he keeps using the same phrases, grammar, style, punctuation, etc. He was reminded by the moderators several times before. I don't know if the moderators' admin privileges give them access to the IP address of those logged in, but it is almost a certainty these user names match.

 

I don't pay a short trip penalty. I haven't turned my car off since I got it 3 years ago, and so it has stayed warm ever since. (When I first turned it on, the dealer had just driven it to the gas station and filled it up, so it was already warm.) This has a number of advantages:
1. The 12V battery is always charged. Of course, since the car is always on, I don't need it anyway.
2. I can park at home with the front wheels on a pair of treadmills. This does several things:
- I get a large number of miles at very low speeds while I sleep, as the car is idling along in electric mode, only turning on the engine periodically to recharge the traction battery. I get great MPG during this time.
- I don't need to use the parking brake when parked, so I don't risk having the cable stretch out from use.
- I don't need to shift to park, so the parking pawl won't wear out either because I'm not using the parking brake.
3. The high levels of carbon monoxide in my detached garage have meant that I don't need to fumigate the structure for termites.
4. I can leave the climate control on auto so that it's always the right temperature whenever I want to go somewhere. The passengers in the back seat are always comfortable too.
5. The oil is much easier to change because it's warm. I also don't have to take out the drain plug in the oil pan, because the oil pump just squirts it all out when I remove the filter.
6. I don't need to worry about my fob battery dying; as long as the car is on, I don't even need to carry it with me!
7. I didn't need to spend $1.98 on two lengths of foam pipe insulation for grill blocking since the engine stays warm. I also don't need to remove or reinstall it seasonally.
8. I can get a climate-controlled garage by just rolling down the windows of the car.
9. I never need to worry about "what's that weird noise my car is making 6 hours after I turned it off?"






Oh, sorry, I guess this thread didn't really need my help in jumping the shark. Well, there it is anyway.

 

Wonderfull! I agree! Except!

I have to disagree with just one thing! There are very low levels of carbon monoxide. The ICE runs very little!

 

Can you explain how that works?

 

Since you mentioned this, I found my notes from many years ago when I experimented with OBD2 software with MPG calculation:

Corolla, city driving, no AC, 74F ambient, cumulative MPG:
1st mile 17MPG
2 miles 22MPG
3.5 miles 25MPG
10.6 miles 30MPG (and that was the average MPG in my commute if AC off)

Subaru, similar conditions:
1st mile 14MPG
2 miles 18MPG
3 miles 20MPG
10.6 miles 22MPG (yap, that car was a gas pig)

And to compare, these are the results from Prius from MPG display (that is up to 10% optimistic as we know), similar commute:
1st mile 25MPG
2 miles 35MPG
3 miles 40MPG
10 miles 60MPG

Looks like Prius has worse short trip penalty than non-hybrid cars. I'm actually surprised!

 

I'm surprised too. Can anyone explain why the Prius seems to have a lower percentage of overall mpg over very short trips than the non-hybrids that Jacek measured?

 

The only advantage Prius has over conventional car is the more efficient (~30%) Atkinson cycle engine. It can't shutdown the engine while warming up so it would behave pretty much like a non-hybrid.

Edit: Regen brake still contribute into Prius during the warm up. Atkinson cycle also produce less heat due to being more thermal efficient. Gen3 exhaust is recycled to make up and speed up the warm up. Gen2 stored the hot coolant in a vacuum bottle to speed up the warm up.