need longer trips (>10 miles) for cold engine,
 

I just can't get good mileage when I start out with a cold engine and only go 10 to 15 miles. Winter makes it worse, but I see it in summer too. Temperatures where I'm at have been around 40F now, and often hit 100F in summer. I've got a Metro (automush tranny unfortunately), and on a 10 mile trip, all city driving, starting out cold, I'll see 28 mpg or so at first and gradually climb to 35 mpg by the end of the trip. If the engine is warm from being driven recently, and I take a 10 mile trip then I start off already at 33 mpg and end at 40 mpg or better.

That's a pretty big difference. I thought of maybe trying a block heater, but I'd need that engine nice and hot, say, 140F minimum. I have the impression block heaters are only intended for very cold climates to get the engine up to maybe 50F tops. So, what to do? Store in hot garage best I suppose, but that's not easy, and is no help for coming home from wherever I went. Some of the crazier thoughts was wrap the engine in insulation? Pour very hot water over the engine before I start? Paint the hood black? Anyone have some more practical suggestions?

I personally say be happy about it. That is.. if you are talking about a commute. If you have a 10-15 mile commute, then you should be ecstatic. If you are talking about trips for errands and what not, then why not just consolidate?

You are on the right path, and seem to be thinking about your options. I am going to guess that most people are going to steer you in the direction of a block heater.

I've seen posts elsewhere from FE people who are using block heaters year round and very happy with them. For exactly the reason you described, bzipitidoo. Of course it takes less long to preheat the engine in warmer weather. And your local sources of parts and installation labor will think you're nuts to use it in warm weather, but that's their view.

From reading around on the topic, it seems the best design is the one that installs in a freeze plug and heats the engine coolant directly.

Not sure about the "tank" type ones that install a tank in the heater hose path - heat has to work its way through the hose into the block, not ideal. Oil pan heaters will warm the oil but not the whole block. Dipstick heaters seem to have the most problems.

Sounds like your thermostat is leaking water past it when the engine is cold. Next chance you drive stop after a mile and see if the radiator is warm while the engine is still cold and that will tell you that the water is circulating before the engine is fully warmed up. If you want more engine heat then block off the grill but not the radiator so that the fan can still work when needed.

Textbook example of a thermostat staying open. replace it and let us know how it goes. toyota parts FTW

28 mpg is not bad at all for a cold engine!! You probably only see this for the first mile, so I wouldn't sweat it. Motor on!!! :)

I installed a tank style 1000W heater in my Tercel and I could not be happier with it. The main reason I chose the tank style was because of the higher wattage and quicker heating capacity. Instead of leaving a lower power heater on overnight, wasting allot energy to ambient heat loss, I have mine setup on a timer for 45 minutes before I leave for work. That is just long enough to start giving me useable heat at startup and drop down to a high temperature idle within seconds.

Another benefit of the tank style heater is that it encourages convective flow through the entire engine (and the heater core too in some cases). When it is installed correctly, the upper hose gets too hot to touch within a couple of minutes while the cold line underneath continually feeds in fresh coolant.

Thanks Snax. Now I understand better about the tank type heaters. Looks like a good setup. Of course you need a good place to put it and route hoses etc. but the concept makes good sense.

Yeah, figuring out the installation was the most challenging part of it. They absolutely must have a sginificant vertical rise without any kinks in the line to work effectively. I ended up having to mount mine down at the level of the oil pan to get enough rise. Anybody with a crowded engine compartment would have a fun time trying to make that work. Fortunately the Weber carb I installed helped to clear the way, that would otherwise have been a royal PITA, for working on it.

I use block heaters on my fleet of vehicles at my job... Napa tank style 15000 W heaters PUT OUT SOME HEAT in a hurry.

15000W is a bit much of a standard duty car, my application is heavy duty F700 box trucks.

Napa sells a 7500W tank style heater and for a good price. I'd install one in my car but I live in an apartment and have no way of having an electrical connection in the parking lot.