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Blocking Air Intake/winter Driving

Discussion in 'Gen 2 Prius Fuel Economy' started by jiw395, Jan 13, 2008.

  1. jiw395

    jiw395 New Member

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    Some time ago I thought I read a thread here regarding blocking off the air intake during winter driving enabling the "ICE" to warm up quicker, and thus increasing the fuel mileage. WELL, I tried it, blocking the upper grill with pipe insulation just stuffing it between the grill sections. The lower section I cut a piece of cardboard, retaining it with plastic wire ties. Well so far on the first day my mpg's increased from 42/43 to 47/49, and now 4 days latter it still keeping the same results, without any over heating issues. I live in the Midwest, temps have been in the low 30's. Last year when temps were much colder, my mpg's were in the mid 20's, at best 28 mpg in the dead of winter, temps in the mid teens, I wish i would have tried this idea back then. But so far it seems to be working,I'll know more exactly when I refill and check actual mileage, which with this increase it might be a week or so since I really don't drive as much being retired, but I will re-post my results.
    Has anybody else heard of this or have any experiance with this procedure increasing engine tempture thus resulting in better mpg's??
     
  2. Clubford00

    Clubford00 New Member

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    There are a ton of posts on here (Some by me) on this subject. I also blocked my grille off -Completely- and my milage went up as well. I live in Chicago by the way. Just be careful if the temp goes above 50 F I noticed that my outside temp guage went nuts above 50. Thats why i bought and today installed the scanguageII so i can keep an eye on all that the regular guages dont.
     
  3. TonyPSchaefer

    TonyPSchaefer Your Friendly Moderator
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    This is my second year blocking. I'm half way through a tank and holding at just above 60MPG. With the colder temps (< 10F) coming up, that might drop into the high 50s before my next refill.

    There have been a few warnings about blocking and CF00 hit on one of those.

    To see the change I've seen in mileage, hit the "Current Mileage" link in my signature. You'll see a noticeable improvement in last year's mileage versus previous years.
     
  4. Clubford00

    Clubford00 New Member

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    Tony i cant figure how anyone can get that kind of milage in this kind of weather. Even in summer when its 85 and sunny out i cant get any better than about 50mpg and have never maintained anything close to 60 i have only had a few 500 mile tanks mostly around 450. Whats your secret? seems like we live close to the same area.
     
  5. TimMan

    TimMan AC or Bust

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    I have to ask your secret dude?

    I increased my tire to 42/40 psi and drive the speed limit now - 65 mph.
    The best I have ever gotten was 56 mpg and that was when it was a mild 60 degrees. When the temp is around 32 and less outside my MPG drops drastically.

    So dude, is blocking the grill the secret??:confused::confused:
     
  6. diamondlarry

    diamondlarry EPA MPG #'s killer

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    I suspect that Tony has been hanging out with Wayne Gerdes in the past.;)
     
  7. Neicy

    Neicy Member

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    Might as well learn from one of the best!
     
  8. diamondlarry

    diamondlarry EPA MPG #'s killer

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    That's what I did.:D
     
  9. JimN

    JimN Let the games begin!

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    There is a "comfortable" temperature range for the car. It seems to like the 50's--mid 70's. Tony has optimized his route, seriously blocked the grill, installed the EBH, and last I heard has an amazingly high tp. Tips from Wayne & Tony are golden.
     
  10. jiw395

    jiw395 New Member

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    Like I said earlier I read this last year, after suffering a winter of mpg's in the mid 20's low 30's. So I thought I'd try it out, took 5 minutes, pipe insulation on top {forgot what size, maybe 3/4 or 1"} and on the bottom I curt a piece of thick cardboard 4 1/4" tall and painted black, {to match the black bra I have installed} and used plastic wire ties to secure, like 4 places. I used cardboard because I wasn't sure what to except, but now since I see it really works, I might go with something better,like luan board, and treat it for the weather. or a piece of plastic sheeting..... Again, it does work...... the results were seen in a 20 minute drive... try it!:D
     
  11. TimMan

    TimMan AC or Bust

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    Cool deal man - thanx for the tip!!!!
     
  12. cyberstout

    cyberstout Alan & Margarete

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    I have followed advice on PriusChat and blocked my grille. We don't drive the car too many miles but I'm sure it will be a help.

    I also have a 1990 Camry that's still in good shape and gets nearly 40mpg in warm weather. Would any of you advise me to block the grill on that car as well?
     
  13. Clubford00

    Clubford00 New Member

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    I would, if the weather is below 30 you should be fine. keep an eye on the Water temp. Maybe to start dont block 100%
     
  14. craftytony

    craftytony New Member

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    Is their a tutorial walkthrough on blocking the air intake? This sounds like somthing very easy to do and that I should try out...

    I also heard that we should try and use gas with no ethanol, but every gas station i go to seems to have 10% :(
     
  15. cyberstout

    cyberstout Alan & Margarete

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    There is a lot of info at:
    http://priuschat.com/forums/prius-modifications/26675-first-morning-blocked-grill-28.html

    I used 3/4" pipe insulation that I bought in six foot lengths. I cut them in half linearly. I just laid it on my workbench and ran a sharp utility knife right down the slit that it came with. I got pretty much two equal half sections. Then I measured the widths that I needed and inserted them from the front. The grille slits are narrower than the pipe insulation so it stays in place due to the compression.
    Some people make small slits where the vertical grille supports are located but I didn't think that was necessary.

    Read the thread to be aware of potential overheating issues. What I got out of it is this:
    Below 32 deg. it's safe to block the entire grill, upper and lower.
    Above 32 deg. and below 50 deg. block only the uppers.
    Probably a good idea to block less than this for extended highway driving.

    All of the gas in our area is 10% ethanol in the winter. I'm not sure if it's that way in the summer months too.
     
  16. JimN

    JimN Let the games begin!

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    Campaign signs work well.
     
  17. egullsfan

    egullsfan New Member

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    After reading numerous threads on this subject, I finally went ahead and blocked the upper grill. Our temps have been in the range of 35-55 degrees during driving time. I do have an EBH and honestly did not notice a huge increase in MPG when I installed that (which kind of ticked me off), but there was some. When I blocked the upper grill, I immediately noticed the ICE shutting off quicker as I started my route. Before, it seemed that the EBH warmth was lost quickly as I hit quite a few lights before getting onto the freeway. Not anymore. I would say my MPG have gone up 2-3 since the upper grille blocking. I'm too scared to block the lower as I don't have a scangauge and it just doesn't get that cold here to risk it. My wife and I both have a Prius, hers is an 07 Touring (package 6 or 7, whatever the highest is) and mine an 08 base model (I got screwed). She is currently getting in the low-mid 30's in MPG (with 11K on the ODO), I'm getting mid 40's (with 2K on the ODO). Our routes are essentially the same to work. I have not tried any of these mods on hers. I know the Touring supposedly get worse MPG than the non anyways, but I truly believe these two mods (EBH and blocking) have made a big difference as well.
     
  18. morpheusx

    morpheusx Professor Chaos

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    you ought to try putting just one piece of the pipe insulation weather strip on the lower section of the grill, it will cover 2 of the 5 slits, I'd say that its completely safe with temps less than 70 degree's.
     
  19. joerdie

    joerdie New Member

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    I blocked 100% top and 75% bottom after reading A TON about it on this forum. I have seen a small increase, (46mpg to 47.4mpg) on my current tank. I am assuming that my increase size will be somewhat smaller as I have yet to finish my break in period. (Only have 500mi so far in the car.) I am somewhat afraid to block that last section in the lower grill for some reason...
     
  20. patsparks

    patsparks An Aussie perspective

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    What I would really like is a replacement for the upper grill to not only block it but eliminate it and smooth the flow of air over the front of the car in the process.