I have been trying something new for me: When I see the lean burn mode cease for a cat cleaning purge cycle I give the car a 'pulse and glide' style accelerator boost. It seems to help average mpg's a bit.
This works best for me when there is a slight uphill section and the lean burn mode is not strong enough to hold the speed, slowing me down gradually during lean burn. When I see the O2 meter jump during a purge, I hit the gas more , taking advantage of the lean burn 'time out' to regain some speed ( and satisfy the pissed off people behind me as well )
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__________________
-Les
2001 5 speed 207K miles.
--- Google 'Peak Oil' and learn what may be coming too soon ---
Location: Colorful Colorado pre-MIMA LMPG=65.5 U.S. post-MIMA LMPG=71+ U.S.
Posts: 299
Re: using lean burn purge cycle to gain better mpg
Funny... I do that too. I can't prove it is better on MPG, but it does seem that way.
I figured... well, it's not going to be in lean burn for 15 seconds or so... might as well gain some speed during this time and take advantage of the extra fuel. You get more HP per gallon the farther open the throtte is also. Doing this, I found a 10 or 15 second purge can be followed by about 3 minutes or more of lean-burn, depending on conditions.
Re: using lean burn purge cycle to gain better mpg
Quote:
Originally Posted by lesdit
... I give the car a 'pulse and glide' style accelerator boost. It seems to help average mpg's a bit.
This works best for me when there is a slight uphill section ... taking advantage of the lean burn 'time out' to regain some speed ( and satisfy the pissed off people behind me as well )
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If I get behind a large vehicle/truck - especially on an uphill section - the "pulse & glide" helps quite a bit! and being behind a larger slower vehicle doesn't incur the animosity of anyone behind me - apart from getting perplexed looks about what I'm possibly up to! (they're clueless of course !)
__________________
Henry Beecher
'06 Sliverstone 5sp
(last MT in CA!)
Re: using lean burn purge cycle to gain better mpg
The easiest way without any special tools is when you are cruising along on a flat. You should see your instant mpg gauge go up to 80, 90, or 100mpg and sometimes hold. That usually means you are in lean burn. Giving a little gas will usually drop you out, but you gain speed. Letting off will put you in reduced fuel consumption, or even fuel cut, but you will slow down. At 45 mph on the flat I can typically hold ~100+ mpg in lean burn. Getting lean burn above 70 - 75 mph is almost impossible on the flat.
Some others have mentioned that you can use a scangauge to see if the car is in lean burn.
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Re: using lean burn purge cycle to gain better mpg
Quote:
Originally Posted by JimIsbell
How do you know you are in lean burn mode????
I notice you have a 5-speed - it should be quite obvious with manual transmission. Just get on a flat stretch of a several mile length going between 45-65mph and play with giving the accelerator as "light a touch" as possible to maintain cruising speed and you're likely to get into lean burn (the MPG will peg around 90). There are computer managed factors which may prevent LBM especially the battery being in a low state of charge. High ambient temperatures also help (but not running the A/C!).
__________________
Henry Beecher
'06 Sliverstone 5sp
(last MT in CA!)
Re: using lean burn purge cycle to gain better mpg
Running the AC will stop Lean Burn? If that is what you are saying, then I know why I have never seen lean burn. I always use AC here in South Texas. The low at night is 75F at 2 AM and by 12 noon it is 90F. There is no way you can live in a car down here between June first and September first, without AC. Maybe after the summer is over I will be able to get my mileage up above 56-57 mpg.
Thanks for answering my question. I now feel better about my mileage.
__________________
Jim Isbell
2000, 5 speed, 250,000 miles
"If you are not living on the edge, well then,
you are just taking up too much space."
Re: using lean burn purge cycle to gain better mpg
Quote:
Originally Posted by lesdit
I have been trying something new for me: When I see the lean burn mode cease for a cat cleaning purge cycle I give the car a 'pulse and glide' style accelerator boost. It seems to help average mpg's a bit.
This works best for me when there is a slight uphill section and the lean burn mode is not strong enough to hold the speed, slowing me down gradually during lean burn. When I see the O2 meter jump during a purge, I hit the gas more , taking advantage of the lean burn 'time out' to regain some speed ( and satisfy the pissed off people behind me as well )
-
I wonder if you removed the cats and then set the car to run in lean burn mode, if there would me any other considerations you would have to consider?
__________________
Jim Isbell
2000, 5 speed, 250,000 miles
"If you are not living on the edge, well then,
you are just taking up too much space."
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using lean burn purge cycle to gain better mpg
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