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Is your grill unblocked yet?

Discussion in 'Gen 3 Prius Technical Discussion' started by cyclopathic, Mar 15, 2012.

  1. walter Lee

    walter Lee Hypermiling Padawan

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    I pulled my grill blocking off several days ago when the temperatures reached into the 70-80 F range. Today, the temperature dropped to the 50-60 F range, so I put the grill blocking back on. I monitor the coolant temps with a ScanguageII(Fwt) -- the highest temp has been 188F.
     
  2. Tideland Prius

    Tideland Prius Moderator of the North
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    Just pulled half of the lower grill block yesterday because I was going on a long highway trip. I'll still leave the rest on until it's consistently above 50F. I've switched to AS tyres.
     
  3. cproaudio

    cproaudio Speedlock Overrider

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    Mine's still blocked 50% on top, 95% on bottom. I rarely hit 190F. Mostly stays below 185F.
     
  4. cossie1600

    cossie1600 Active Member

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    I am not sure why most of you guys bother. The coolant system comes with a thermostat. It will block the intake of coolant into the engine when the temp isn't high enough. Maybe if you live in Canada. It's as stupid as warming your engine before you take off.
     
  5. k9frog

    k9frog New Member

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    I removed my grill blocking awhile ago, for me it didnt seem to do much, but i also was messing with the dealer and i didnt want them to see the blocking i did
     
  6. szgabor

    szgabor Active Member

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    And this is your guess right ????

    Some of us who actually monitor the car with something, actually KNOWS that you are wrong....(unless where you live no colder than 50F in the morning).

    The warm up cycle is "significantly" shorter ... so if you start out in suburbia or in a city and do not hit highway in 1 mile ... your engine will not stop at redlights or a glide etc.

    Also if you would like a little cabin heat a little faster blocking makes a big difference ... again if your morning temp stays 50+ all year ... you do not need this... but there are plenty of "colder" places other than Canada !!!

    Yes, "warming" up the car in most cases is not needed but this is technique is different .. since I DO monitor the car and keep full record I CAN tell you that this matter in your MPG (if you care of course).

    Just my 2 cent ... and by all means do not block your grills but do not be so opinionated either of things you never tried ...
     
  7. MJFrog

    MJFrog Active Member

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    I know a 1.8L engine is larger than a 1.5L, but it still has a lot of surface area to radiate heat. Even if you don't do a lot of Pulse/glide the engine is designed to shut off frequently, and in colder weather it will lose a LOT of heat...quickly.
     
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  8. revhigh

    revhigh MPG Enthusiast

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    It definitely makes a difference. I believe it also makes quite a difference aerodynamically. I've gotten 1.5-2 MPG improvement with the grill blocking. I may leave it in all year long. My scanguage tells me there's no difference in running temps.

    REV
     
  9. revhigh

    revhigh MPG Enthusiast

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    Because we ... unlike you .... have done testing, analyzed the differences, and found them to be significant, rather than just saying something with no facts to back it up.

    REV
     
  10. cyclopathic

    cyclopathic Senior Member

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    not sure I have seen contradictory points on this one. Here a few points:
    - Per Volvo up to 30% of aerodynamic drag comes from radiator
    - GMs 80MPG Precept with Cd 0.19 ([ame=http://en.wikipedia.org/wiki/General_Motors_Precept]General Motors Precept - Wikipedia, the free encyclopedia[/ame]) had radiator mounted in the back
    - Toyota states that active shutters improve Cd by 0.01

    It looks like most of the MPG savings come from faster engine warm up, not from better aerodynamics.
     
  11. revhigh

    revhigh MPG Enthusiast

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    Seems to me like you're saying two different things .... unless I'm not reading it right ! :D

    REV
     
  12. fuzzy1

    fuzzy1 Senior Member

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    Having been in fresh snow six of the past seven days, I'm not yet ready to reduce grill blocking on either car.
     
  13. cossie1600

    cossie1600 Active Member

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    I have dataloggers too, not just you. I also know the car comes with a thermostat, your engine receives very little coolant before it reaches operating temperature anyway. You can block all the grill you want, it still doesn't change when the thermostat open.

    I agree on better aerodynamic. I also agree that you might keep heat in the engine better by blocking airflow to the actual block itself, but is it really worth the time for people on the snowbelt? Give me a break.

     
  14. szgabor

    szgabor Active Member

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    And why do you think the Volt had this built in (I think few other car as well).

    Actually the heat retention is just one thing the drag reduction is another ...

    Oh yes they just bother with it ....

    Most car is designed to run under a very wide range of conditions so yes you need to be able to cool the engine (and in prius's case the inverter) when it is really hot outside and the radiator's efficiency is low ... but you do not need that MOST of the time especially winter ...

    So in my case I block the grills to reduce the air flow through the engine compartment that help reduce drag (not much, but some, I drive very little at highway speed where this would make much of the difference for me). AND the grill blocking reduces the time needed to complete the warm-up-cycle of the car (only after which engine stop will occur). Whether or not it makes a measurable difference depend on the type of driving you do ... let say you drive three hour nonstop (like highway not traffic etc) yes the warm up cycle doesn't matter that much BUT if you drive shorter distances more often in colder weather IT WILL BE measurable...

    Now, this make very little difference when the car's base MPG is around 20 on highway and 16 in the city .... (then do not bother ...) but with my car I can ad a few more MPG I "estimate" over 2 actually it worth for my time to put it on and take it off once a year ....

    Sorry to repeat some of the points...
     
  15. cossie1600

    cossie1600 Active Member

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    As I said, I understand the drag part and the heat retention part. I am just saying it doesn't really help you warm up the cooling system too much faster as the coolant is controlled by the thermostat. If you live in Canada or somewhere cold, it definitely doesn't hurt. In southern New England or NJ? Give me a break. I guess if you pull your car immediately onto the interstate maybe.

     
  16. F8L

    F8L Protecting Habitat & AG Lands

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    In hilly terrain or for pulse and glide sessions the heat retention can be very important. My work is located approx. 1/2mile from the freeway so by the time I enter the freeway I am not even at full operating temp. I pick up a little more heat during the next mile of freeway but then I have a long downhill grade that I try to warp stealth down. In the winter I am limited by engine temp. Once temp drops much below 170deg F the engine kicks on an ruins my warp stealth glide. With grille blocking I lose heat more slowly and able to extend this high speed glide quite a bit. Sometimes enough to make it up the next small grade without lighting the engine. Does it make a huge difference? I don't know but for the minimal cost and effort involved with grille blocking it is worth the fun. :)
     
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  17. rebenson

    rebenson Member

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    Pulled mine off when 70's around the 11th. My 1st winter doing it, and it was so mild hard to say if it did anything. Guess will see next winter...
     
  18. bisco

    bisco cookie crumbler

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    took mine off today. completely forgot about it and noticed when my wife was washing my car.
     
  19. macman408

    macman408 Electron Guidance Counselor

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    Hey, where I live, it's usually over 50°F when I drive, and I still block my grill. I can get to the first engine stop (40°C) in about a half mile that way. In the summer, I leave it partially blocked, and hit the same point in about 0.3 miles. It also helps retain heat better when the car is off.
     
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  20. revhigh

    revhigh MPG Enthusiast

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    As I said above ... I have ABSOLUTELY no doubt that my winter mileage is better for blocking the grill. 1.5 - 2 MPG better. I'm sure it's a combination of aerodynamics and warm-up reasons.

    All I know ... is I'm going to continue doing it, and monitor it, and maybe leave it in permanently if my Scanguage continues telling me that there's no increase in operating temps. If that's the case, I may build a total block out of black plexiglass perfectly fitted for that area. Only the monitoring will tell though.

    REV