Steady decrease in FE?
#1
Steady decrease in FE?
Hello all. I've had my HCHII since May 2007, and have been getting on average 47-49mpg per tank. Putting snow tires on in December (Blizzak WS-60 on lightweight alloys) dropped that down to about 38mpg. I understand that increased friction/rolling resistance and low temps will take their tall on FE, but should I be seeing that much of an impact? The route is the same 15miles every way, mixed highway/town roads, with hills in several spots. Even on warmer days I am seeing sub 40mpg numbers lately. Tires are at 34psi. The car has about 10k miles on it so far. I am thinking next step is checking air filter and also fuel- I've read that some gas stations now sell E10 fuel in NYS, and that could have a big FE impact. Comments/suggestions?
#2
Re: Steady decrease in FE?
Yes, in addition to adopting the recommendations that follow, always expect the winter fuel economy to be lower. How much lower? Well, it depends not only on the weather conditions but also on how diligently you follow the recommendations we offer.
Anyhow...
1- Pump up your tires. I suggest setting the rear tires to 38 PSI and the front to 40 PSI as a start. Another popular setting is 40R-42F and even 42R-44F. The higer the pressures the better the FE. Its that simple.
2- Don't warm up idle the car before driving off.
3- Block your front grille.
4- Install and use a block heater
5- Avoid (if possible) gas brands that add ethanol as an oxygenant agent.
6- Use the DWL and DWB technique liberally. The DWL is VERY useful in the first 5-10 minutes of your drive.
Cheers;
MSantos
Anyhow...
1- Pump up your tires. I suggest setting the rear tires to 38 PSI and the front to 40 PSI as a start. Another popular setting is 40R-42F and even 42R-44F. The higer the pressures the better the FE. Its that simple.
2- Don't warm up idle the car before driving off.
3- Block your front grille.
4- Install and use a block heater
5- Avoid (if possible) gas brands that add ethanol as an oxygenant agent.
6- Use the DWL and DWB technique liberally. The DWL is VERY useful in the first 5-10 minutes of your drive.
Cheers;
MSantos
#3
Re: Steady decrease in FE?
I guess this means back to the good old "human optimization" to work around slightly imperfect hardware
Going into HCH purchase I pretty much assumed this is still somewhat of a beta test and that's ok with me. It does work rather well for the level of complexity involved (especially when compared to regular cars)
Will do more reading and see if I can get the FE back to reasonable numbers. Now, as far as avoiding gas brands with ethanol- how would one go about finding that information and would there even be such a choice in a state like New York?
Going into HCH purchase I pretty much assumed this is still somewhat of a beta test and that's ok with me. It does work rather well for the level of complexity involved (especially when compared to regular cars)
Will do more reading and see if I can get the FE back to reasonable numbers. Now, as far as avoiding gas brands with ethanol- how would one go about finding that information and would there even be such a choice in a state like New York?
#4
Re: Steady decrease in FE?
Yes, in addition to adopting the recommendations that follow, always expect the winter fuel economy to be lower. How much lower? Well, it depends not only on the weather conditions but also on how diligently you follow the recommendations we offer.
Anyhow...
1- Pump up your tires. I suggest setting the rear tires to 38 PSI and the front to 40 PSI as a start. Another popular setting is 40R-42F and even 42R-44F. The higer the pressures the better the FE. Its that simple.
2- Don't warm up idle the car before driving off.
3- Block your front grille.
4- Install and use a block heater
5- Avoid (if possible) gas brands that add ethanol as an oxygenant agent.
6- Use the DWL and DWB technique liberally. The DWL is VERY useful in the first 5-10 minutes of your drive.
Cheers;
MSantos
Anyhow...
1- Pump up your tires. I suggest setting the rear tires to 38 PSI and the front to 40 PSI as a start. Another popular setting is 40R-42F and even 42R-44F. The higer the pressures the better the FE. Its that simple.
2- Don't warm up idle the car before driving off.
3- Block your front grille.
4- Install and use a block heater
5- Avoid (if possible) gas brands that add ethanol as an oxygenant agent.
6- Use the DWL and DWB technique liberally. The DWL is VERY useful in the first 5-10 minutes of your drive.
Cheers;
MSantos
What does DWL and DWB mean?
Thanks,
TDSOUP
#6
Re: Steady decrease in FE?
In Washington state you can't get anything but gas with 10% in it from mid fall to mid spring it is mandated by the state.
You also have to remember, a 10% reduction in mileage @ 47 is far more of a hit than 10% at 15 mpg in other words, if I take a 10% hit for gas & a 10% hit for the cold and a 10% hit for snow & slush on the road I am looking at maybe 34 or 35 mpg....I am running about 36-37 right now so that does not sound too far off.
In my truck at 15 mpg, if I make the same allowances, it comes out to about 11, I am getting about 12 right now, so, well that sounds about right too.....the difference is I am taking a 3mpg hit in the truck & a 10mpg hit in the HCHII yet it works out to about the same % drop.
You also have to remember, a 10% reduction in mileage @ 47 is far more of a hit than 10% at 15 mpg in other words, if I take a 10% hit for gas & a 10% hit for the cold and a 10% hit for snow & slush on the road I am looking at maybe 34 or 35 mpg....I am running about 36-37 right now so that does not sound too far off.
In my truck at 15 mpg, if I make the same allowances, it comes out to about 11, I am getting about 12 right now, so, well that sounds about right too.....the difference is I am taking a 3mpg hit in the truck & a 10mpg hit in the HCHII yet it works out to about the same % drop.
#7
Re: Steady decrease in FE?
Sure.
The best way to explain this in a way that be can clearly understood is to read Tarabell's article.
Consider this a biblical must read for any HCH-II owner serious about getting great Fuel Economy.
Cheers;
MSantos
The best way to explain this in a way that be can clearly understood is to read Tarabell's article.
Consider this a biblical must read for any HCH-II owner serious about getting great Fuel Economy.
Cheers;
MSantos
#9
Re: Steady decrease in FE?
I think blizzacks have a max of 35 psi on the sidewall. I wouldn't recomend exceding the limit, although some have on this forum. I think your biggest hit in FE is in the weather and winter fuel blends.
Also, did you go with OEM tire sizes for your blizzacks?
Also, did you go with OEM tire sizes for your blizzacks?
#10
Re: Steady decrease in FE?
Over the past weekend, I did mostly highway driving, and decided to check the mpg, and it was back to the range I was accustomed to seeing before the onset of winter:
https://www.greenhybrid.com/compare/...r.php?cid=5679
My conclusion is that the tires are fine, and probably will fare even better regarding mpg as they break in. The maintenance was probably fine. I attribute the drop in mpg's to the cold weather & short commutes.
I use pipe insulation now in the grille when it's really cold out, and remove it on warm days, or when I have a long trip to make (I'm afraid of the engine overheating on a long drive; not sure if I should be concerned about that or not). I check the tire pressures, and am currently setting them at 36-38 psi (max pressure listed on sidewall of tires is 47 psi).
There isn't anything I can do about the short commute. My job is close to my house, but I work at night in a dangerous area, and walking or riding a bike isn't safe, so I drive.
Overall, the car is performing well so far, and I'm glad I bought it. Even on the worst days, 34 mpg are far higher than what my old car achieved (18 mpg city in winter w/ same short commute).
Last edited by Gairwyn; 02-11-2008 at 12:27 PM.