Poor MPG in first 5-10 miles

Engine Block Heater.

:welcome:

 

Keep the car in Eco Mode for the warm up period and maybe also turn the heating off or low for the first 5 mins. Both of these stop the engine running more to heat itself and the cabin.

It does work.

 

Yes, poor warm up MPG is a 'feature' of any internal combustion engine, and one that the Prius often magnifies by focusing on good emissions and gentle start up loads, which usually involves recharging the HV Battery once you are on the highway.

Combining trips, an engine block heater, insulating engine wrap, a garage, all help some.

 

Did you check if that decreases you fuel use per the trip vs MPG reading?

 

Hi dzawski,

I avoid routes with long stop lights for the first 3 miles, then stay off the interstate (or any road with sustained 45 mph or faster) for the next 3 miles. This way, when its time for high engine power, its not wasting it on the catalytic converter, by running the engine rich.

I also have the temperature control Auto OFF , like others have suggested.

I am getting close to my second Gen III tank fillup at 65.6 mpg (indicated) for 530 miles...

 

I really would not worry about it since unless you get a block heater there is not much you can do

Just think any other will be the same unless you get a plug in

 

Hi J-C and TPS,

I am lucky that I have a routes which are not right onto a main street. So, I can do the 15 mph during the Stage 1, and avoid pulling the battery down too far.

 

My point is while the #3 option will give you higher MPH than option #1, you also increase trip miles and your total fuel use (= miles:MPG) will be the same if not worse.

I use #2 technique and don't see depletion of battery or MPG penalty later. Maybe this is because I have to go uphill in the first mile and the first mile uses BOTH battery and ICE for propulsion (easily to see on my energy monitor). If I went slowly in flat terrain in the first mile, maybe that would result in the same problem you have with #2.

I personally get 60-70 MPG (per the display as I'm yet to refuel) on my 10 mile city commute and I always accelerate at the point where power begins or sometimes well in the power zone (going less would be blocking traffic in my city) and then glide as much as I can till the next red. The huge variation of the MPG depends on the timing of the glide and red light timing.

 

I try to keep the climate control & defrosters off until the ICE is warmed up. However 60mpg doesn't do you any good if you can't see. At a stop if the ICE runs just to power the cc then turn it off.

Every morning I take a tour of the parking lot when I get to the office. The HV battery is highly charged so taking our service road around the South Building lot then crossing the road to the North Building lot will add .1 or .2mpg to the tank average as I'm cruising between 20-25mph on electricity. Going home I take the same route so the ICE can warm up at relatively lower speeds.

If I'm making quick stops, 5-10 minutes, then I keep the car on & just lock the door to prevent the startup cycle loss.

 

Put a high power space heater immediately under the engine bay and leave it on all night.

 

Driving extra (useless) distance just to rack up a few high MPG miles to pad your average....somehow I can't see the sense of this.

 

Initial mpg is only 25. How terrible is that. The number to focus on is the average mpg. You could also park overnight on the highest point in your city and coast for 5 miles or so. Ride a bike to the parking spot everyday. Solves 2 problems -- mpg and cardio health.

 

In addition to the EBH and driving slow (where possible) for the first 3-5 miles, in colder weather you should use a grill block. I was amazed at how much shorter the warm-up period was after I installed it the first time.

 

Climate control gets heat from the engine. The longer the engine stays cold, the longer your period of low mileage.

Tom

 

My morning commute starts on residential streets with 4 stops to the highway 1.5 to 2 miles away. The car stays outdoors. Running the CC or defrosters does not increase coolant temp especially over the minute or so waiting for the traffic light. Yes, coolant temp will rise to 125F or so before the highway but not enough to provide heat without the ICE running. By the next light or two on the highway (probably another couple miles at 50mph) the temp is high enough to provide heat without the ICE running.

There are three routes at the end of my commute. The distances are approximately equal. The difference is in the posted speed limits. I choose the route with the lowest posted speeds. The travel time is roughly equal depending on traffic & timing of the traffic lights.

 

Ah, but in your original post, you asked how to get better mileage in the first 5 - 10 minutes and an Engine Block Heater would do that. Still, the pollution from the power company (even if predominantly coal) would be less than your tail pipe.

I wouldn't bother depleting your battery coming home. While the engine may be running the next day (to warm up the car) it also now have to spend time recharging your spent traction battery. And if you believe what people wiser than I have mentioned, the car is using more battery power in the first few minutes of a cold engine start, thus you are depriving your car of an energy source, forcing the burning of more gasoline.

Cheap solution = grill blocking.
Cheap and effective = grill blocking with EBH.
Cheapest solution = leave it be.

The general consensus is to run the car a bit easier the first few minutes, rather than running harder.

The engine provides heat to the cabin, thus if you run the heater, you rob the engine compartment of insulating heat.