Lots of techies on PC have talked about grill-blocking in cold weather to help the Prius gain mileage as its engine warms up more quickly and saves heat. An article that I posted to the Hybrid News forum says that GM has incorporated grill blocking into the Cruze Eco model to improve aerodynamics at high speed: "To achieve the efficiency of the Cruze Eco, engineers . . . installed shutters to close off part of the grill at higher speeds to reduce wind drag . . .." Based on reports from folks on PC, it might improve mileage. Don't know if it would be worth the cost. Don't know if GM has patented it. Does anyone know if Toyota is considering doing this, either for heating in cold weather or aerodynamics, in future models of the Prius?
Ford is also offering it on their new focus as active grill shutters. Not sure if Toyota is looking into it or not though, I haven't seen reports about it.
I would hope that Toyota goes one better then putting in mechanical shutters. These are trouble before they even get started....mechanical parts rust, get clogged with dirt, bugs. I would hope with Toyota engineering, they can come up with a electronic means warm the engine and keep it warm.....without the mechanical shutters.
It would be cool if it were offered. Besides the fact that other car makers are offering it now, we brought up grille blocking w/Doug Coleman in Detroit.
Would be helpful. I could avoid my neighbor walking by and asking me with bewildered look and furrowed brow what the heck I'm doing as I stuff foam pipe insulation into my grill. Automating it would eliminate this inconvenient and undesirable social situation.
i blocked my grill with pipe insulation back in january but havn't noticed a mpg increase. now i'm wondering if the pipe insulation is increasing drag?
Did you block the top or bottom grills. ??? Blocking the radiators really does make sense. It prevents the cold air from taking heat away from the hot anti-freeze, which the driver is requesting that it be warm enough to heat the cabin. If you prevent the cold air from taking the heat away, the ICE has to run less to keep the anti-freeze at a temperature that will keep the driver warm. Less running of the ICE = better MPG. If it does cause a air drag,,,,,I'm guessing that you just have to give this up to get something else in return.
Bisco, two thoughts. Firstly, I had been wondering about the effectiveness of a $2 mod like grill blocking, too, assuming it was mostly useless, but just had an epiphany today with my new toy (Scangauge). It will keep the heat in, but it could very well be relatively useless if you don't know when enough heat has built up to use hybrid system features like EV or engine off. In the past I would keep guessing, slowing down, speeding up, etc., until the damn thing turned off in cold weather. Now I know exactly. Second, I was surprised in my 34°F ride home tonight to see that coolant temps reached 190°F easily after a couple not-steep-at-all ascents, and that was with the engine off most of the time gliding! I only have bottom 3/5 blocked with driver's side not totally covered anywhere, and top 1/2 covered (well, top 1/2 cause the other half fell out at some point), so fully blocked like yours with sustained driving might be too hot for your engine. Gen II in particular lower grill driver's side shouldn't be blocked fully...
Blocking the grill will not -increase- air drag. It -may- decrease it a bit. We do it not for the mileage, but to avoid shivering while driving! I doubt Toyota would incorporate it in the Prius design, as the cost would likely exceed the benefit, especially to Toyota.
Don't forget snow! The energy for electronic warming of the engine comes right off the MPG. Toyota has done a pretty remarkable job at getting the engine up to temperature efficiently. The majority of improvement will need to come from keeping it from cooling off (e.g. grill shutters).
Here is a link to the article in the USA Today about "Shutters". Drive for higher mpg gives automakers case of the shutters - USATODAY.com This honestly seems like a no-brainer to incorporate into a Prius for grill blocking. A modulating valve with a simple PID based on coolant temp could control the temperature pretty accurately. Those types of valves operate for hundreds of thousands of cycles if not millions in Thermolaters and lots of other stuff. Happy driving, Chris
I'm surprised Toyota hasn't done this already, considering they added the complicated coolant heat thermos system, gas tank bladder, etc.
What radii temp are you getting in GEN 3? I'm running about 10 degrees higher than GEN 2. Gen 2 blocked in winter running around 181-185. Un blocked GEN 3 running at 191-196,???
I recorded my mileage and daily temps last year. I did the same this year with the Bottom blocked 100% and the Top 50% (passenger side). With my scangauge to keep an eye one engine temps. This year I had about 2 mpg better ( calculated) in comparable temps. I wish someone with some sheetmetal or plastics experience could offer a block instead of the tubing. Heck, I'd even operate it with a string near the driver's seat.
they already did with using exhaust heat exchanger and heated coolant thermos. Speaking about shutters, they used to put manual cable controlled shutters in old days.. they were as prone to fail as your trunk/hood cables. And rust bugs and dirt would not be concern if designed properly.
