Last post on Oct 14, 2008 at 3:34 PM
You are in the Subaru Forester
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Subaru Forester, Wagon
#1 of 29 PZEV Considerations
Aug 14, 2008 (2:40 pm)
I'm looking at the 2009 Foresters and have the option to buy one with PZEV engineering. I'm not in a state which requires that technology but would probably get it just on principle unless there are significant drawbacks to it (mileage, power, etc.)
Any information on the trade-offs between the two engines?
#2 of 29 Re: PZEV Considerations [ron106]
Aug 15, 2008 (7:45 am)
We have a PZEV and so far we're happy we spent the extra $200 or so to get it.
You actually get 5 extra horses, or 175hp total.
Throttle response is immediate even at low revs. Acceleration on the highway is much more responsive than the 165hp 2002 Legacy it replaced, and that Legacy had the advantage of being a manual transmission.
My wife and I drove out of town on Wednesday and had a friendly competition - she averaged 30.0 mpg driving up, while I only managed 27.0mpg coming back, though I think my speeds were higher. So we're quite pleased with the fuel efficiency we're getting, too. High so far was 34 mpg, with a low of 22mpg in city driving.
Besides the 5hp, another potential benefit is that all the emissions equipment is designed to last at least 150,000 miles, because in PZEV states (NY, CA) the emissions warranty is that long.
I'm not sure if the regular, non-PZEV engine is all that different, but these and the obvious green benefits of the PZEV upgrade were well worth it to us.
#3 of 29 Re: PZEV Considerations [ateixeira]
Aug 15, 2008 (10:03 am)
That's great news. I couldn't find much information on google but you certainly confirm what the salesman said. I brought the car home yesterday and the mileage rose from 14 at the dealer's lot to 24 when I got home. I think I'm sold!
#4 of 29 Re: PZEV Considerations [ron106]
Aug 15, 2008 (11:10 am)
They let you take it home? Nice dealer...or did you buy it already?
#5 of 29 Why does PZEV increase hp and mpg?
Aug 16, 2008 (6:53 pm)
I have read that the PZEV engine will increase horsepower and miles per gallon. A subaru salesman I spoke to recently wondered why that would be since most of the time stricter emission technology decreases performance. Any responses?
#6 of 29 Re: PZEV Considerations [ateixeira]
Aug 17, 2008 (7:47 am)
I bought it! Going on the first 100 miles.
#7 of 29 Re: Why does PZEV increase hp and mpg? [kotterman]
Aug 17, 2008 (1:19 pm)
It depends on how the stricter emission policy is met. If an engine can be made more efficient then it makes better use of the hydrocarbon fuel ingested, and this means more power and cleaner exhaust. With the technology today, mostly computers and faster-acting electronic controls this can be done more easily, especially if just fine-tuning an engine design that is already pretty clean.
In the older days this was not possible, so the engine ended up being detuned which hurt power. Things like lower compression, ultra-lean fuel mixtures, and retarded timing caused lower performance, poor economy, and a lousy running engine in general. In those days the fine tuning was done by adding extra controls each designed to handle certain things, and many times they didn't all work very well together.
On paper, if an engine could be 100% efficient it would get fantastic power output and fuel mileage, and truly be zero emissions. Since this is not possible there will always have to be something like a catalytic converter to clean up what does come out the exhaust pipe. The combination of fuel economy standards and emission policies has driven the technology to a great place.
#8 of 29 Re: Why does PZEV increase hp and mpg? [bigfrank3]
Aug 17, 2008 (2:00 pm)
Thanks for the explanation. So does the Subaru Forester PZEV increase the miles per gallon as well as the horsepower?
#9 of 29 Re: Why does PZEV increase hp and mpg? [kotterman]
Aug 17, 2008 (3:03 pm)
My guess is it could, but probably not measurable. The changes made to get 5 HP should not be many or large, I would think just some of the calibration settings. 5 HP is not much of a change but as the old saying goes, better to have it than not. I would expect that the window sticker for the mileage is the same, so you would be better off watching the reports of mileage that come in here. Most of what I have seen here are better than the sticker anyway.
Juice has a PZEV and it is not broken in yet, but he is already getting great mileage... although his wife does better.
#10 of 29 Re: Why does PZEV increase hp and mpg? [bigfrank3]
Aug 18, 2008 (3:04 am)
I live in Minnesota where the Subaru dealers do not sell PZEV vehicles. I am considering purchasing an 09 Forester in the next few months. Do you think it's worth ordering a Forester with PZEV and waiting for the order to come in instead of getting one off the lot? In your opinion, does PZEV make a big enough difference in the performance of the vehicle to do a special order?