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-   -   improving cold start FE [throwing around ideas] (https://www.fuelly.com/forums/f9/improving-cold-start-fe-throwing-around-ideas-5077.html)

Erdrick 06-18-2007 06:49 PM

improving cold start FE [throwing around ideas]
 
There are a lot of great ideas on the site that deal with aerodynamics, driving techniques, modifications, and other FE-related things. The one thing that I haven't seen much interest in (perhaps I just missed it though) is overcoming the low FE that is inevitable after first starting your car.

Diesels have long employed engine warming blocks to help get heat ciruculating in the car faster, and to improve cold winter starts. This of course helps the engine avoid some damage that it would have incurred if it had been started without any assistance from a heat-producing device.

Are there any other things that we should be looking at which might help even out the FE you get while driving your car?

The fact is, long trips yield better MILEAGE than short ones (think 100 miles compared to 5 miles), but you end up using WAY MORE FUEL on the long trip. Let's say you get 10mpg and drive 5 miles. You end up using half of a gallon of fuel. Now let's say that you get 50mpg. You drive 100 miles. You end up using 2 gallons of gas.

While this may not be a great example, it is only for demonstrative purposes. If we could improve the 10mpg cars economy even by a little, there would be marked fuel savings.

I believe that if we were able to get that 10mpg car up to optimal operation conditions right off the bat, that the FE of said car would be much better.

So the question is... what do we need to change to make this happen?

For a diesel, it ends up being a block warmer. Some people swear by low weight synthetic oils. We need to think outside the box though, and come up with entirely new ways of approaching this FE robbing part of our journey.

Any ideas??

zpiloto 06-18-2007 07:23 PM

Engine block heaters are not just for diesels. I had one on the Maxima and it made a hugh difference, around 10% if i remember. You're right the shorter the trip the bigger gain you'll see with the EBH( do a search for EBH). I've tried warming the engine oil on the stove to 200 degrees and then reinstalling with some sucess but it is a bit of a hassel. You're on the right track there is about 3 MPG on my 25 mile commute between cold and warm engine temps.

CO ZX2 06-18-2007 07:33 PM

Engine heaters and insulation.
 
I copied this from a Challenge FE report I made in April. I have been using this procedure ever since. I am in closed loop in about 1/4 mile, used to take 3-4 miles. Get your car headed the direction you want to go the nite before.
No engine warmup....get moving as soon as possible.

April 1, 2007 9:37 PM MDT

Winter is not over yet here in Colorado. It has been snowy and 15-20 degrees at night for the past week. I have not driven the car at all this week till yesterday.

Scanguage readings for week March 26 thru Apr 1, 2007: Trip to neighbor's garage 6.2 miles 122 mpg. One way because car is still there. Saturday morning temp 16 degrees. Our places are close to equal elevations but there is a 200 ft. gradual drop and a 200 ft. steeper rise between us. The balance of the distance is fairly level. The best previous mpg I remember seeing at this distance is 82 mpg(summer). So the belt and component deletions with the added cold-start-warm-up techniques are responsible for considerable gain for this stretch.

I have taken the time to make room in the garage for Old Reliable. I have been working on making my cold starts and the first part of my trips more mpg productive. The past few days I installed a block heater I have had for months and installed a heater in the water hoses. Also put on an oil pan heater, this may end up on transmission later. All were on for about 8 hrs overnight Friday. Also put R-30 insulation batts between engine and hood overnight to help hold the heat. Used R-30 batts all around the bottom of the car from the garage floor up around the body. Made sure my battery was fully charged as alternator is still off car.

GasSavers_BluEyes 06-18-2007 09:51 PM

Quote:

Originally Posted by zpiloto (Post 59220)
I've tried warming the engine oil on the stove to 200 degrees and then reinstalling with some sucess but it is a bit of a hassel.

Check out www.summitracing.com I believe they sell oil warming pads. It basically sticks to the bottom of your oil pan and plugs into the wall to pre warm the oil.

atomicradish 06-18-2007 10:19 PM

Is this actually cost effective?

lol @ warming the oil on the stove

rh77 06-19-2007 12:09 PM

Ebh
 
I second the motion on the Block Heater. I've been using one for about a year now, and it helps tremendously, even while garaged (if I can only figure out how to heat up the car as it's parked away from home for extended periods :rolleyes: )

The Automatic Transmission is my biggest problem with cold starts (and, well, I guess overall). I'd like to heat up the fluid somehow -- perhaps that stick-on heater would work on the transaxle as well -- or a dipstick-style heater?

They say it's more efficient to use the power grid than your own engine to heat itself up. I'm sure there's a cutoff point, but it have to draw quite a bit of juice to do so...

RH77

landspeed 06-19-2007 01:54 PM

Block heaters are good - especially a 2.7kw one like mine. When it is working! Because it heats the engine up in 15-20 minutes, it means that you don't 'vent' heat to atmosphere all night as you would with a 300 watt one.

If you get a wideband lambda sensor, you may find a certain throttle position that puts the mixture to 14.0:1 even when cold - my car does this, and it is better than flooring it (10.0:1), or driving along very gently (10.0:1 ratio). Driving with the right load can help the economy a lot by avoiding wastage of fuel.

CO ZX2 06-19-2007 03:04 PM

Quote:

Originally Posted by rh77 (Post 59335)
I second the motion on the Block Heater. I've been using one for about a year now, and it helps tremendously, even while garaged (if I can only figure out how to heat up the car as it's parked away from home for extended periods :rolleyes: )

The Automatic Transmission is my biggest problem with cold starts (and, well, I guess overall). I'd like to heat up the fluid somehow -- perhaps that stick-on heater would work on the transaxle as well -- or a dipstick-style heater?

They say it's more efficient to use the power grid than your own engine to heat itself up. I'm sure there's a cutoff point, but it have to draw quite a bit of juice to do so...

RH77

Rick, I am using the oil pan heater on my transaxle now. Works good.

I would not recommend a dipstick heater at all. They just do not have the heating capacity to do much.

diamondlarry 06-19-2007 03:15 PM

I have a block heater in my Prius and it works great. I can reach 150*F(min temp for stage 4) in ~1/8 mile. When I come to the stop sign about 3/4 mile from my house, all I have to do is come to a complete stop and let the engine stop on it's own to to reach stage 4 which means that all of the hybrid functions are in operation.

LxMike 06-19-2007 04:42 PM

Quote:

Originally Posted by CO ZX2 (Post 59359)
Rick, I am using the oil pan heater on my transaxle now. Works good.

I would not recommend a dipstick heater at all. They just do not have the heating capacity to do much.

which oil pan heater are u using?? i was looking into on this past winter but seeing as most of my trips are shorts one it might be good for year round. might even get 2 1 for oil pan and one for tranny pan??


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