Engine insulation for hybrids to improve fuel economy

[Talos Woten]

Originally Posted by Phase

Well having it at the middle is the peak fuel economy area right? Because I’m getting horrible city mpg… not to mention I lose heat pretty fast when my car switches to ev mode

Those are all classic signs the hybrid engine isn't warm enough. You'll definitely see gains by doing the engine insulation, both in fuel economy and warmup time.

So the correct solution is: do both! Do the engine insulation *and* in cabin extra spot heating. As my friend Rajan says: "Anything worth doing, is worth doing to excess."

[hayden55]

Try it out phase. Get a gauge of some sort and slap some heat mods on. I get 55 on short trips and 60mpg on long trips in my 2010 prius. City mpg wise.

[Phase]

Originally Posted by hayden55

Try it out phase. Get a gauge of some sort and slap some heat mods on. I get 55 on short trips and 60mpg on long trips in my 2010 prius. City mpg wise.

I ordered some 1 inch thick ceramic fiber mineral wool. Getting some bubble aluminum to wrap it in. Doing the mod next week when it’s sunny. Stuff should be in the mail soon!

[cRiPpLe_rOoStEr]

Originally Posted by Phase

Velcro would be on the other side of the insulation from the engine. Attached to the hood right? I’d just have to use an adhesive than can handle heat

Hadn't any option suitable to high-temperature been provided, Velcro would be easily damaged whenever the insulation is off.

[Phase]

Originally Posted by cRiPpLe_rOoStEr

Hadn't any option suitable to high-temperature been provided, Velcro would be easily damaged whenever the insulation is off.

i used these. they are like plastic clips and very thick and hard. its not like normal '' fuzzy'' velcro

https://www.velcro.com/products/indu...ts&color=black

[Phase]

will be fabricating my insulation this week. one inch thick ceramic fiber minerol wool, covered both sides with reflectix foil insulation, and foil tape sealing the edges. total cost is about 60-65 dollars without mounting points done

[Phase]

Got the ceramic fiber wrapped in insulating foil and trimmed down ti fit a little better so the hood will close. Hope I’m doing this right

[Piwoslaw]

Just remember to take it out when going for inspection/tune up, or you will get an earful about how parts are damaged from overheating, risk of fire, etc.

[Phase]

Originally Posted by Piwoslaw

Just remember to take it out when going for inspection/tune up, or you will get an earful about how parts are damaged from overheating, risk of fire, etc.

im going to try and attach it to the hood later this week

[Ecky]

Just came across this thread, and unfortunately I'm coming into summer, so it isn't a whole lot of immediate use, but I do have a few thoughts to add:

It might be worth exposing an airflow path around the coil packs. These are probably pretty heat resistant, but being excessively warm might reduce their lifespan.

The results speak for themselves, but I have some skepticism about the mechanism by which it's believed to work. An insulated ceiling does virtually nothing if the windows are open, so to speak, and I wonder if the added insulation between engine and hood isn't instead functioning mostly to fill space that air would otherwise be flowing through, rather than actually insulating a heat loss path through the hood.