Data with & without Block Heater anyone?

[Zendriver]

I'm having trouble finding posts (I know I've seen them!) with data before and after block heater installs. I'm trying to figure out what the average increase in coolant temp is (after the "thermos dump"). And first 5 min mpg comparisons.

In a 35-45F garage, I'm seeing numbers like 80-100F by the time I hit the bottom of the driveway after 3 hours of heating and it seems low...am I expecting too much? I thought I remembered similar numbers after the thermos transferred over.

I plugged it into a Kill-a-watt (cool device...google it!) and the heater's drawing 395-405 watts pretty consistently. Tonight I'm going to try the manual thermometer (literally placing my hand on the block to see if it's getting warmer).

On a related topic, are there any hints for cold-weather/short trip driving tips? I seem to be in the low 40's for a 6 mile commute (EBH in the AM only). But I got >50 in warmer (>50F) weather.

PS - I'm going to keep track for a couple days and see what happens.

[JimboK]

80-100F seems about right if you're waiting any length of time (like driving down your driveway) to take a reading. If your car's been sitting overnight in those ambient temps, the thermos contents will be cooler than what's in the rest of the system. The thermos dump normally occurs almost immediately after starting, transiently dropping the system coolant temp. Take a look immediately after startup. I've seen it anywhere from about 110F to 140F then.

(Actually, it's puzzling to me why there's so much variation. It doesn't seem to depend on OAT. I've been thinking of posting this in a new thread, but maybe the EBH experts can help both of us. Hobbit? FireEngineer? Others?)

But I digress. I haven't paid as much attention to how low it drops as to the initial temp, but I know I've seen it below 100.

As for tips, consider blocking your grill to conserve the heat the EBH provides. Between the two, you will have earlier and more frequent opportunities for ICE-off glides if traffic and route conditions allow.

What are your typical conditions, BTW? Speed? Terrain? Number of lanes? Traffic volume? Expected slowdowns or stops (e.g, predictable traffic, red lights, stop signs)? Give us a little description and maybe one of us can offer tips specific to your commute.

[Zendriver]

I knew I could count on this board for a quick reply...thanks!

I think my answer is take another route with fewer lights even if a bit longer...and block the grill. Getting the instant coolant temp before the thermos xfer seems like a good idea.

re: driving techniques:

My commute is your typical suburban nightmare:
-7 or 8 miles
-50 mph roads (jammed with cell-phone jabbing SUV drivers who get upset if you don't "jackrabbit" start)
-13 traffic lights in one 3 mi section (who planned this???)
-none are synchronized (no way to predict...other than if you see a green one in the distance, hit the brakes because you'll never make it...) only once in the 4 years have I made it from end to end without a red light!
-one hill out of the neighborhood, but more or less flat

P&G doesn't work well since lights are too close to get much glide, and generally >41mph...but I try stealth glide/glide that when I'm not tailgated.

On the consumption screen I seem to get something like:
25 40 50+ without the EBH
35 45 55+ with it

I only have 1000 mi on it (the prius)...so both it & I need to be broken in a bit more.

I think my answer is take another route with fewer lights even if a bit longer...and block the grill.

[Rangerdavid]

Definately block the grill!! Its one of the cheapest mods available, and its certainly effective! Not as much as the EBH, but complements it nicely, and only takes a few minutes. I think your temps are in the "normal" range and your EBH is working properly. I see slightly higher temps, but my grill is blocked.

the mileage on my first 5 min. bar has increased from 20-25 mpg up to the 40-45 mpg range. A drastic increase in my book. I've used 3 tanks since FireEngineer did my install, and am averaging 52.8 as of this afternoon. Thats up from about 45 mpg before the EBH and grill block.

I'm currently experimenting with my commute, trying alternate routes to and from in order to assess the route for best mileage. Even one or two are longer, but here in the mountains, I'm looking for the flatest route, fewer hills.

[JimboK]

Zen, it looks like you've tried, or at least are aware, of most techniques that might help. I have some specific comments below.

I think my answer is take another route with fewer lights even if a bit longer...and block the grill.

You're on target with both. When traffic and road conditions do allow ICE-off glides or EV mode (see below), your warm ICE will be more willing to comply.

I'm still experimenting with alternative routes and occasionally finding ways to fine tune the drive. Some may be longer, so I'll try one a few times and compare the average MPG to the old route to make sure that overall fuel consumption drops. I enjoy the challenge of pushing the numbers higher, but I keep the big picture in view.

My commute is your typical suburban nightmare:
-7 or 8 miles
-50 mph roads (jammed with cell-phone jabbing SUV drivers who get upset if you don't "jackrabbit" start)
-13 traffic lights in one 3 mi section (who planned this???)
-none are synchronized (no way to predict...other than if you see a green one in the distance, hit the brakes because you'll never make it...) only once in the 4 years have I made it from end to end without a red light!
-one hill out of the neighborhood, but more or less flat

That's tough. Hobbit's work suggests that mid-speed ranges are the least efficient. So it looks like you're forced to accelerate, cruise for a period of time at this inefficient speed, then lose all that wonderful kinetic energy when you get hit with a sudden red light. Is that about it?

You didn't say how you're monitoring your coolant temp. Can I assume it's a ScanGauge? If so, watch your RPM and keep it below 2300 or so as you accelerate. You'll still find you can accelerate at a pretty good pace (unless you're working up a hill), fast enough to keep most would-be tailgaters at bay.

If you can't find an alternate route, work on learning the timing of the lights. Though they may not be synchronized, you may find individual lights to be predictable. Anticipate their change and begin your slowdown, as traffic allows, when you see a stale green.

P&G doesn't work well since lights are too close to get much glide, and generally >41mph...but I try stealth glide/glide that when I'm not tailgated.

So you obviously know about P&G, and it looks like you've explored its capabilities and limitations. One thing I've been doing in these conditions is "pedal-feathering" EV mode (no EV button) to extend a glide or maintain speed for short distances -- both below 41 MPH of course -- or as the sole source of propulsion for closely spaced red lights. For example, if I see a stop light in the distance that I expect to be red for me, but it's too far away to begin slowing without inciting road rage, I apply enough pedal to induce EV mode. On level terrain the car will actually accelerate, and maintain speed on an ever-so-slight uphill. I'm careful not to deplete the battery too much, and I do this only if I know subsequent driving will likely recharge it.

On the consumption screen I seem to get something like:
25 40 50+ without the EBH
35 45 55+ with it

That's pretty respectable.

I only have 1000 mi on it (the prius)...so both it & I need to be broken in a bit more.

Agreed. Keep practicing and have patience. It's taken my car's driver over a year to get really broken in!

Finally, if you haven't already done so, check out CleanMPG. The focus there is on maximal fuel economy regardless of vehicle. Lots of helpful folk there too.

[efusco]

I posted this at someone's request over at Cleanmpg.com yesterday...thought it might be pertainent here...
<div align="center">

Month	2003	2004	2005(EBH/part. grill blk)	2006(EBH/full grill blk)*
OCT	45.2	53.7	53.1	59.2
NOV	45.2	53.1	55.5	56.4
DEC	43.1	50.6	50.6	58.2
JAN	44.1	49.3	54.6	58.4
FEB	48.2	50.8	49.4	57.9
MAR	49.5	53.5	55.8	64.6

*First year with careful use of acceleration b/w 1700-2300rpm also.
Much nicer table HERE
</div>

[Zendriver]

Thanks for all the helpful comments Jim, Ranger & Dr. MD! This board has been a fantastic resource during the steep part of the learning curve (I'm still on it!). It's great to read messages from like-minded folks going through the same things that I've either been through or about to experience.

I have a "AutoXray EZ-Scan 4000" which is a handheld (clunky) version of the Scanguage. I bought it to reset the idiot light on my previous car after a couple months of winter gas. I'm thinking of upgrading to the Scanguage since mine takes 3 key strokes to see what I want each time and it times out at ~10 minutes without a key being pressed. Same general functionality, but it's more of a diagnostic tool than a driving guage...and 10x as big.

So...I think I'll try the grill block, accelerate in the sweet spot 17-2300, avoid lights by adjusting routes and adjust my mpg expectations for short trips in winter. If that doesn't work I can bike occasionally to make up for it!

;-)

My guess is that accelerating with a cold ICE (redundant?) it may be better to favor the low end of the rpm range. I'm thinking if the engine has to turn anyway to warm itself up, it may as well be providing some acceleration. In other words: trying to minimize the revolutions when the engine is not pushing the car. If the cold snap lasts I'll experiment a little.


Happy Easter everyone!

[JimboK]

<div class='quotetop'>QUOTE(zendriver @ Apr 5 2007, 10:43 PM) [snapback]418578[/snapback]</div>

I'm thinking if the engine has to turn anyway to warm itself up, it may as well be providing some acceleration. [/b]

It must be your zen, vibes, or whatever: Today I speculated basically the same thing and tried a different tactic on the first part of my morning commute.

From the driveway I turn onto a two-lane road, mostly hilly, 45 MPH limit, for about a mile and a half. It's in a mostly rural area, but with moderate traffic as folks from outlying subdivisions use it as a commuter route. Even with the EBH, the ICE is usually not warm enough to cut off, so I've been using a hill-country, cold-ICE variant of P&G: maintain speed or accelerate up the hills (whichever happens with RPM kept within its target range) and ICE-on glides down, keeping top speed below 41 as traffic allows (not always possible). On the glides I've often dropped it into neutral, which assures that the ICE stays at the lowest RPM and burns as little fuel as possible. At the end of the mile and a half is a stop sign, and by then the ICE is usually warm enough for an ICE-off glide up to the intersection. From there I turn onto another road that's ideal for P&G: less traffic, more level.

Today's change: Again keeping the RPM in its target range, I accelerated to as high a speed as possible, while staying safe and avoiding tickets (the locals like moving radar). I maintained it with a lower RPM, but still within the target range. I used ICE-on glides again to moderate speed as needed. Of course I got to the next road segment and its P&G opportunities more quickly. The net effect: My first five-minute MPG was close to 50, as high as I've ever seen it first thing in the morning. It served the added benefit of not worrying about holding up traffic behind me.

After reading your original post, I've also been watching my coolant temps after the intitial reading to see how low they go after the thermos dump. Yesterday it started at 128 and dropped to 100, OAT about 40. Today it started at 104 (actually the lowest I've seen it with the EBH, which makes the 50 MPG five-minute reading even more impressive) and dropped to 83, OAT about 30. This seems to validate your findings.

[mywhitenoise]

<div class='quotetop'>QUOTE(zendriver @ Apr 4 2007, 08:47 PM) [snapback]417934[/snapback]</div>

I knew I could count on this board for a quick reply...thanks!

I think my answer is take another route with fewer lights even if a bit longer...and block the grill. Getting the instant coolant temp before the thermos xfer seems like a good idea.

re: driving techniques:

My commute is your typical suburban nightmare:
-7 or 8 miles
-50 mph roads (jammed with cell-phone jabbing SUV drivers who get upset if you don't "jackrabbit" start)
-13 traffic lights in one 3 mi section (who planned this???)
-none are synchronized (no way to predict...other than if you see a green one in the distance, hit the brakes because you'll never make it...) only once in the 4 years have I made it from end to end without a red light!
-one hill out of the neighborhood, but more or less flat

P&G doesn't work well since lights are too close to get much glide, and generally >41mph...but I try stealth glide/glide that when I'm not tailgated.

On the consumption screen I seem to get something like:
25 40 50+ without the EBH
35 45 55+ with it

I only have 1000 mi on it (the prius)...so both it & I need to be broken in a bit more.

I think my answer is take another route with fewer lights even if a bit longer...and block the grill.
[/b]

Do you live in Elk Grove? You described my town 100%. I hate it.

[Zendriver]

<div class='quotetop'>QUOTE(JimboK @ Apr 6 2007, 08:36 AM) [snapback]418734[/snapback]</div>

Today's change: Again keeping the RPM in its target range, I accelerated to as high a speed as possible, while staying safe and avoiding tickets (the locals like moving radar). I maintained it with a lower RPM, but still within the target range. I used ICE-on glides again to moderate speed as needed. Of course I got to the next road segment and its P&G opportunities more quickly. The net effect: My first five-minute MPG was close to 50, as high as I've ever seen it first thing in the morning. It served the added benefit of not worrying about holding up traffic behind me.[/b]

I'm impressed! A (nearly) 50mpg bar for the 1st 5 minutes in 30F weather!?!? That has to be unprecedented! I can only dream of such results. By the end of that 5 min did your ICE get to stage 4 temp (164F)? Wondering how much of the good result is getting to the P&G road faster...curious if the entire route mpg was better or not.

Hey...if this technique works maybe we can call it "pulse and putt" (maintain speed with minimal RPM's)!

So the recipe for good mpg in cold weather is something like:

1. A healthy number of cold-weather mods:
---Engine Block Heater >3 hours
---Blocked Grill to trap EBH heat and prevent losses when under way
---Oil fill level / viscosity for weather

2. Pulse and Putt until engine is warmed sufficiently (Stage 4???)
---Pulse = Accelerate at 1700-2300 rpms
---Putt = maintain speed using ICE in range of 1700 +/-
-----------(minimizing battery arrows???)
---Probably best to avoid heater use during this time (if you and passengers can take it!)

3. Pulse and Glide with speeds <41mph
---Pulse and Warp-stealth Glide >41
---------At all times when using the ICE attempt to maintain 1700-2300
---------When not in use seems to line out at 960rpm