2010 Prius Grill Blocking strategy

I have been reading everyones post about grill blocking. Today I blocked the lower grill 100%...first thing that I noticed was how much quieter the ICE was when going up a hill. I have never seen this mentioned before, but that part is really nice. As for the MPG, it was only 1 trip with temps about 32F, but I think that I will see a increase in the MPG...since I did not lose any MPG during this trip. With MPH at 65 most of the time, not loosing MPG is a plus.

Thanks for the tip PriusChat !!!!!!

 

Just got my Scan Gauge in this week. First run on highway in the high 60MPH with 100% lower block had the temp running in 190F within a few minutes after getting on the highway and a few times hitting 195F. That Hybrid Winter Survival Guide was stating that the optimal engine operation temperature is 60-90C. Converted to degrees farenheit, 90C is 194. It sounds like I am running at the upper end of the range. Sure, the car make take longer to warm up if I didn't block or blocked partially, but wouldn't the ICE run more efficiently at around 167F(75C)(and hence help prolong the life span of the engine) instead of consistently being at the high end if I do a good amount of highway driving? Or is highway driving still going to cause the coolant temp to linger in the 190F's even without blocking? I had zip-tied the foam tubes on already and hence didn't really want to cut them off to do a comparison test and was hoping if anyone already checked out the differences.

 

IMHO, Most engines are supposed to run at 190 or so,thats what the thermostat and fan are supposed to keep it at. (and what a non hybrid engine temp gauge will show- it hold steady ) . The higher temp. helps the fuel vaporize easily, and the computer can back off on the fuel injector on time. I too, block 100% bottom and it helps the engine keep its warmth during glides or downslopes. The prius engine is super efficient to start with, and and when you add the ICE shutoff on a glide or stealth period then it cools down quick. I can do a 6 mile down hill glide starting with a 190 degree engine and end up at 140 at the end, with no blocking. Blocking really helps. Highway runs with blocking stay in the 180-195 range .

 

From my SGII observations over 22,000 miles, it looks like the Prius has a 195 degree thermostat as that is where it will sit at when cruising at highway speeds for prolonged periods, regardless of outside temperature. I block 100% lower in the winter time, starting when daytime temps are in the low 60's or less.

 

thanks for all the info. It is reassuring to know that people are in general consensus. Manuel(Hybrid Survival Guide: A Hybrid Owner’s winter survival guide - CleanMPG Forums) does sound to be on the conservative side. His guide states that the radiator fan kicks in at 90C(194F) which is the temperature I hit on the highway, but Ken has the fan threshold at 203F. Is Manuel getting his number from the average of the Prius and Insight, as his guide is addressed to hybrids in general?

 

Hi Ken,

Just read through that whole Saga with IK. Which is kinda OT for this thread. But had to comment.

Somebody is really messing with IKs head. My guess its he is getting the double barrels of a marketing crap from somebody close to him, who he values the opinion of. It did not make any difference that the Prius was better than any other car for his circumstances.
Circumstances, that most likely would be better served by Amtrak passenger train, than a car, but he chose to satisfy his requirements with a car.

With all the Prius left on dealer lots of late, I am afraid this marketing approach is having an effect. I see this as a big tradgedy for the Prius in the US. I know this car is selling like hotcakes in Japan. But, I fear its going to be a weak seller here in the US.

And part of it is also due to a dishonest design approach to the Gen III Prius. This is a car design intended to con the sports car desirous youth into buying something good for them, rather than what they want. In effect, its the Clotaire Rapelle approach to selling hybirds (rather than SUVs). Its not an approach intended to sell a car of the type the Prius is, to the customers who want the type of car the Prius is. Its Toyota doing what we as American car buyers hate so much about marketing of cars by US companies (except maybe Ford of late).

And the IK saga points up how badly this can back fire and for the first time giving traction to the FUD anti-marketing by Toyota competitors.

In the end, I think IK just felt duped. Even though he did get the best car for what he wanted a car for (unless there are money problems in the Kingdom), it did not matter. He felt duped. And this is never a good thing for a car company cause its customers. He goes on and on and on bashing the Prius, when all the foundations of facts are completely the reverse. He comments on the 30 % reduction in illegal speed highway driving winter, quartering winds fuel economy - when no other car is going to do as good in such a situation. But, just because the car is so good in the summer, and comes back to earth in the winter that alone is a reason to bash the Prius. This is totally irrational. But, it does not matter to him - if he can bash the Prius he is going to - and I think its because he felt duped. So, he apparently has no problem making all these irrational conclusions (those not founded in common sense).


As I read through page after page, I realised that any rational presentation of the facts to IK illicited a bashing vieled in phony baloney pretense of rationality. I had to ask myself why does he feel duped, since apparently he feels he can retaliate by attempting to dupe (contiously or sub-contiously its not clear). And it clicked with me, that the basic design dishonesty of the 3 rd Generation Prius is key - a fuel economy car, that has design details, that cost money, or end up being poorly realized to make it seem like a car that should be screeming around an IMSA track. The configuration of the 3rd Generation Prius is at the heart of the issue. It starts with the 1.8 liter engine - a choice probably made on economy of scale and marketing not the economics of the metropolitan driving user. This then ripples through the car pushing and pulling things into less usable form.

The center console further confounds - using up knee room, and front space. This with the larger engine bay results in the smaller rear seat, which no longer has the cup holders in front (not enough room) but uses up the center seating position.

Now, the engineering of the 3rd Generation Prius, after having been stuck with the 1.8 engine decision, is first rate. The car is advanced significantly. But because of that bigger engine (and requisite heaving wheels/tires), its not pratical to realise any fuel economy improvement by the metropolitan driver over the 2nd Gen.

Note to Moderators - I attempted to send this privately to Ken, but he has that feature disabled....

 

prelim results for blocking. tracking my new work commute which is 9.1 miles over mostly 40 mph roads. generally trips take around 16 minutes. i am seeing roughly 2-4 mpg in improvement over time. problem is, my commute changed prematurely due to fire so guessing since i did one tank with no blocking (overall tank mileage was 47 mpg) and one tank with blocking (current tank in sig) the current tank in sig only had a few days of "before fire, 100 % grill block. so...

now, i did the same thing last year with zero block, 100% bottom, zero top, and 100% bottom, 50% top and the difference from the first to latter was over 6 mpg.

so grill blocking does help and the slower your commute, the more it helps. now, thought about re-doing the zero block on the new commute, but probably (at least hoping!!) dont have enough time to do that before my Leaf arrives...

bummer... i am sooooo disappointed that i cannot do that...lol!! yep really bummed

 

Thanks for all the grill blocking info. I decided to try this on my new prius less than 800 miles on the odo. First run 50 mile commute to work 40/38 tire psi, 10 degree temp, cruise set at 65mph, no blocking. Result 42.4 mpg Next day same temp and route 100 percent lower block and 50 percent upper. Result 45.2 mpg. So a noticeable improvement. Tomorrow I will try 100 percent lower with no upper same outside temp expected. I am a little nervous about upper blocking without scan gauge. Def noticed quicker cabin warm up with blocking. Also set auto temp to 70 for this experiment. This is my first prius and am loving every min of it so far.

 

Ok, so after one tank with no grill blocking, and dealer tire pressure of 36/35 I got around 41 mpg. My commute is mostly highway and some slower roads. Now, I pumped up the pressure to 41/40 and did a 100% lower and 50% upper, I have no scangauge, but ken says its ok.......? 1st run today, I'll see how she feels.

 

Ken,

Just wondering if you could possibly clarify this:

"I believe the temperature of the inverter coolant is "cooler is better", between ambient temp and 50C(104F) vs 88C(190F) engine coolant temp"

What should be the safe operating temp range of the inverter coolant? I just recently programmed the xgauge to display the inverter coolant. It has been displaying no higher than 50(I'm assuming farenheit according toe Adrian Black's code spreadsheet) so far. What is the safe upper limit before I need to start removing my lower grill block? And if "colder is better", than wouldn't it be even better if the temp is lower than 50C/104F?

 

I did this to FL and back to Wi with no tyraps . they stayed in and had no problem for 3200 miles. Got back last week.

 

I find this Velcro tie strip material effective for securing pipe insulation. If temps start climbing it's easy to remove and or re-install. Lee Valley has it:

Velcro® Plant Tie - Lee Valley Tools

 

This is an update on my grill blocking. I now have DRL blocking the upper half of the top grill. I still have the lower grill 100% blocked. I have a digital cooking thermometer fastened to the inverter under the hood.I ran the thermocouple wire to the center council where I have the remote reading unit . My highest temps so far are 20 degrees above ambient. It is quite cool in WI. yet but will be traveling to FL. soon. I will keep a close eye on the temps. BTW I found the digital cooking thermometer on craigslist for 5.00$. That can be an inexpensive alternative to a scan gauge. Larry

 

have Sis working at Ford, i did her online class on the 2012 Focus hoping to get some info on the EV version, but nothing to be had other than a short intro that essentially said nothing, but one thing i did see is the new "efficiency" trim package that besides the better engine tuning, suspension/tires thing also has a computer controlled front grill louver system that will optimize the engine temps and aerodynamic efficiency

pretty cool... made rain sensing windshield wipers easy to forget

 

Question about coolant temp reading on Scangauge. It's still cold here, but wondering for the future...

I see Ken says engine coolant temp is safest under 190°F, with some people reporting spikes to 195, 197, etc. Is it necessary to XGauge in the inverter coolant temp as well, or is it safe enough to go off the pre-programmed "fwt" gauge for engine coolant, and just keep that under about 190?

 

I haven't been watching the inverter coolant, but Ken says it should be under 65°C.

In general, with electronics, the cooler the better, so when it gets warm you should unblock the grill in front of the inverter's radiator. If you have a Gen II as your profile says, that's the lower one. If you upgraded to a Gen III (since this is, after all, a Gen III forum), then unblock the upper one.

 

1st I just got my Gen 3. Radi temp is running 10 degrees higher than Gen 2 at 190-193 vs. 181-184. is that normal? How do I change Scan Gage to show inverter temp?

 

I have the bottom totally blocked. The temps are getting warmer here in Western NY, should I leave the bottom blocked? The top has been open all winter. Should that have been blocked during the cold weather?

thanks