Short Trip Myth

Where does it say that longer drives don't have to face the short trip penalty on this or any other forum or website? And thus propagating this second myth you bring up?

It is only logical that one must progress through the warm up cycle when driving longer distances as well. It has already been pointed out that this penalty is mitigated by the higher mpg obtained following the warm up cycle so that the average mpg for the trip is higher.

SCH-I535

 

Short Trip Math

As the car warms up, the initial, low MPG for each mile rapidly improves. However, the trip average MPG is the average of all miles traveled up to that point:

	Column 1
0	[tr][th]mile[th]MPG[th]0[th]1[th]2[th]3[th]4[th]5[th]6[th]7[th]8[th]9
1	[tr][td2]1[td2]25.0[td2]25[td2][td2][td2][td2][td2][td2][td2][td2][td2]
2	[tr][td2]2[td2]37.5[td2]25[td2]50[td2][td2][td2][td2][td2][td2][td2][td2]
3	[tr][td2]3[td2]58.0[td2]25[td2]50[td2]99[td2][td2][td2][td2][td2][td2][td2]
4	[tr][td2]4[td2]68.3[td2]25[td2]50[td2]99[td2]99[td2][td2][td2][td2][td2][td2]
5	[tr][td2]5[td2]74.4[td2]25[td2]50[td2]99[td2]99[td2]99[td2][td2][td2][td2][td2]
6	[tr][td2]6[td2]78.5[td2]25[td2]50[td2]99[td2]99[td2]99[td2]99[td2][td2][td2][td2]
7	[tr][td2]7[td2]81.4[td2]25[td2]50[td2]99[td2]99[td2]99[td2]99[td2]99[td2][td2][td2]
8	[tr][td2]8[td2]83.6[td2]25[td2]50[td2]99[td2]99[td2]99[td2]99[td2]99[td2]99[td2][td2]
9	[tr][td2]9[td2]85.3[td2]25[td2]50[td2]99[td2]99[td2]99[td2]99[td2]99[td2]99[td2]99[td2]
10	[tr][td2]10[td2]86.7[td2]25[td2]50[td2]99[td2]99[td2]99[td2]99[td2]99[td2]99[td2]99[td2]99
11	[tr]

• 25 MPG mile 0->1 - this is the initial warm-up penalty, the universal, minimum short trip, as well as acceleration from rest, 0 mph to neighborhood 25 mph speed
• 50 MPG mile 1->2 - the warm-up continues and includes acceleration from 25-to-0-to-27 mph for STOP signs and acceleration to 27 mph
• 99 MPG mile 2->3 ... 10 - the warm-up is done and the per mile, MPG is at a constant 27 mph

Every extra mile 'dilutes' the initial warm-up and stop-start fuel burns so the trip average smoothly increases. This continues to improve as the distance covered increases because each subsequent mile adds another 99 MPG segment. It is part of a series:

MPG(trip) = MPG(1) / 1​

MPG(trip) = ( MPG(1) + MPG(2) ) / 2​

MPG(trip) = ( MPG(1) + MPG(2) + MPG(3) ) / 3​

MPG(trip) = ( MPG(1) + MPG(2) + MPG(3) +MPG(4) ) / 4​

. . .​

This math increased my tank MPG simply by converting my ~13 mile commute to an ~27 mile commute. By adding 'laps' at 99.9 MPG before parking at work, each commute moved the per tank MPG up from a normal 52 MPG to 91.8 MPG:


No one can escape the 1st mile, MPG hit due to warm-up and initial acceleration. But we can dilute this 'short trip' penalty by adding high MPG miles to the trip. In my case, 'doing laps' on a loop where the car achieves over 99.9 MPG.

A marathon drive is not about 'getting somewhere' but a Prius 'bowling trophy' showing what can be accomplished on a well planned route. The rest is using a lazy man's protocol for high mileage, efficient driving.

Bob Wilson

 

Your attempt to use a new definition for "short trip" is what's causing such a stir.

SHORT TRIP = LESS THAN 10 MINUTES OF DRIVING

It's that simple.

 

That's the rub... you can avoid them.

We tell owners to run their errands while the engine is still warm. That will result in less gas being used than driving later after the system has cooled down. You plan to stop by the store on your way home or combine several trips into one.

Also, don't forget that the plug-in model provides a solution to the brief drive penalty. So, there really is a difference that is being directly addressed by the upgrade.

The thing we can agree on is how poor of an efficiency measure MPG is. It doesn't represent how much fuel is actually being consumed. It's just a end-result calculation with no reference to distance traveled.

 

Time to change your forum name, "troll" just rolls off the tongue, still need a little definition but wait...it's coming

You have the option of request "a" thread be removed by the moderators, it's done when senselessly, downwards spiraling threads appear and they continue to sink.

 

This is inaccurate. Simply take a longer route to reach your destinations so all trips will be long enough that the 'cold-soak' warm-up costs disappear.

Bob Wilson

 

The first 5 miles of a trip when the engine is cold uses more gas. So if you can combine your errands while the engine is warm you will use less gasoline that if each stop you made was originally from a cold start.

 

Short trip is a myth busted, for Plugin Prius (PiP).

 

Reminds me of the old cartoon:


Bob Wilson

 

I got my PiP for $25k after the incentives. It is better equipped than the Three. I do a lot of short trips or very long trips. PiP is the ideal vehicle for it.

 

So far this tank of gas I have 1925 miles of short trips all combined into 999MPG in August I will make a long trip 250 miles and I will have my warm up combined in with this trip. Warm up should not hit me to hard.
My definition of a long trip, Is short trips!