Effects of Short Commute (mpg, maintenance, etc.)

We have the same commute! I drive just over 3 miles each way and I always go home for lunch as well. I have driven the car 300 miles thus far and I am averging 47 mpg's. This includes a 60 mile trip from the dealership home which is basicaly all highway driving. So I can't complain with the mpgs i am getting now compared to what i was getting (17mpg) Hopefully someone will chime in with some good thoughts as it will benefit me too

 

the sweet spot for mpg,,, is driving at least 5miles or more on a trip,,, going anywhere from 30-50 mph..... i just recently did a 46 mile trip going 35-50 mph,, and getting 71mpg.......

 

1) I encourage you to drive a longer distance every other week.

a) the Engine Oil need to get hotter than 212F to drive out water
b) the 12 volt battery needs time to recharge

2) if you don't drive longer distances,

a) reduce the mileage between oil changes
b} a 'battery minder' a charger of under 2 Amps, may keep the 12 volt battery in fine condition.

 

I don't have the c, but I've been driving my Gen II on a 3-mile commute for 5 years now. I don't go home for lunch though, and for 8 months of the year I ride my bike about 50% of the time. So the occasional longer trips on weekends or vacations help out the overall mpg level quite a bit.

With a scangauge to track the warmup stages, tire pressure at 40/38 generally, and using pulse and glide when possible, I average 49 mpg.

There's a detailed description of the warmup stages (for Gen II, but it's probably pretty much the same) at http://techno-fandom.org/~hobbit/cars/five-stages.txt (written by and for nerds, FWIW). Yes, for us short-commuters, it's tough to get to stage four, but stage 3 is still effective if you drive at the right speeds. For my Gen II, in stage 3 you go to full no-ICE when the engine coolant temperature is >157'F and you're above 35 mph and then coast or glide. I'm not sure of the details for temp and speed for the Gen III/c cars.

 

Excellent thread - thank you. I have essentially the same commute (but not home for lunch) and I am seriously considering a C, but I was also concerned about these same issues. I am thrilled that you're getting in the 40's. My current 1998 Civic gets about 22 MPG for my commute. Are you on fuelly.com? I'd love to follow your MPGs over time. The Cs on there right now are doing mostly highway.

 

Warmup stages in recap, for Gen II:
1a - Just powered on, first half-mile - ICE comes on, but all drive power is from electric battery. If car is coasting or stopped, then the ICE will recharge the battery, otherwise, it's wasted energy. When driving with some pressure on the gas pedal, you can feel a little surge when you go from 1a to 1b.
1b - gas engine is now ready to power the wheels, and battery power is used only if needed.

2 - engine is above 40'C (104'F), and gas engine will turn off at stops (if the heater isn't on, etc.) Note that the energy display will show the engine is off when coasting at speed, but it's not really. That's why at slow speeds, you don't get 99 mpg, but maybe 90, 85, etc.

3 - engine coolant is above 70'C (157'F), gas engine will truly turn off when not needed at speeds between 35 mph and 41 mph (and will stay off until needed, so you can coast down to 30 mph). Car stays in stage 3 (usually) until you come to a complete stop for 6-7 seconds. The engine will then turn off with a little lurch and you are now in stage 4

4 - Gas engine will turn off when not needed at any speed under 41 mph (for Gen II, later cars have a higher limit). Above this speed, the engine doesn't consume gas if not needed, but it still needs to spin due to mechanical limits, so pulse and glide isn't as effective, and the energy screen doesn't go to a no-arrows state.

I have seen cases where the car is turned off for a short period of time (run into a store), and it's still warm when you turn it on and it starts right off in stage 4. I have also seen cases where the car was in stage 4, I had a long glide to a red light, sit at the light for awhile, then when I continue driving I'm back in stage 3, even though the engine temp stayed above 157'F the whole time. It must be monitoring the catalytic converter temp as well, maybe something else too.

 

Excellent thread idea! I've been wondering the same thing since my new job is very close to where I now live. Thanks for all of the helpful replies, gang!

 

My commute, while in a Gen II, is about the same. Seems silly to drive such a short distance, but it'd take 30+ minutes by bus whereas by car it's about 10.

I've been getting mid 30s for most trips. Not that great, but since most of those are all short trips, I'd say it's not bad.

I find I achieve the best MPG by working from home.

 

While short trips may prevent the ridiculous MPGs some get, using techniques like grill blocking and engine block heaters can help a lot! I can see 60 mpg on a mild sunny day after driving less than 4 miles!

 

Yeah, I forgot to mention I block the grill (not sure how helpful it is, but it's cheap) and I use an EBH whenever the car is sitting in temps overnight of under 50'F. The EBH definitely helps on short commutes, but you still probably won't make any money back on it. It does help get the warm air blowing sooner though, if you use that (I just wear a coat for the 7 minutes to get to work, who needs heat? Except for defrost to keep the windshield clear).

But my days of a short commute might be coming to an end. Our workplace is moving in June to all of 10 miles away, but we're pretty much all looking for new work anyway because work conditions in general have degraded considerably (new boss, layoffs, etc.)

My main interest is not MPG but GPM (gallons per month). In that respect, a short commute shines. I fill up about every 3 weeks. Including vacations and such I still average less than 14 gallons/month. In the old days with a 14 mile commute and a car that only got 24 mpg, I was using nearly 50 gallons/month.