Surprising fuel performance

C_Parker

Pre-takeoff checklist
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I've been getting surprisingly good fuel performance from my 182. I'm wondering if you guys are getting similar results or if there may actually be some issue.

I tend to pull back while cruising because I'm typically sight seeing. I cruise at 18" and 2300 RPM. I'm taking off at 5-6k DA and cruising between 7-11k feet MSL.

I hand calculated 9.0GPH and 11.2MPG (statute miles). I feel like that's pretty good for the average track log speed of 135MPH. This is in a stock 1963 182F without wheel pants or any mods.
 
18" is nothing. 9gph is not surprising. Sounds about right to me.
 
18" is nothing. 9gph is not surprising. Sounds about right to me.

Right.... That engine isn't making any power at 18" and 2300... It shouldn't burn any fuel.
I like my engines running up higher... I personally wouldn't lug it down that low. It is all opinion though.
 
I should have prefaced this with the POH data which claims 10.5GPH at those same conditions. Also keep in mind that at my DA's 18" can be full throttle at cruising altitude.
 
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I should have prefaced this with the POH data which claims 10.5GPH at those same conditions. Also keep in mind that at my DA's 18" can be full throttle at cruising altitude.

Can easily account for the difference by leaning.
 
You need to provide a bit more data. Do you have engine monitoring? How are you leaning? It may be you are actually on the LOP side of the curve. I regularly fly a IO540 at 8.3 gallons per hour but that is about 60 degrees LOP.
 
It sounds about right for low power lean of peak.
 
Sounds pretty close to me if you are lop. on my io550 I get 8 gph at 15" 2300 and 8.7 at 15" 2400.
 
I'm definitely not LOP, I don't know that you can even get LOP on this thing. I don't even lean to a stumble and then back off, I just keep the EGT needle straight up on the gauge which has no temperature markings.
 
What engine do you have? If you aren't lop I would think those numbers are a little low for the power setting. What does the POH say for that power?
 
Your numbers are similar to what I've seen. At 65% or less I lean as far as it will go and still be smooth (it isn't LOP in our plane). I've seen 135 KTAS (yes, knots) at 13,000', 9.2 gph. 182Q with wheel pants.
 
What engine do you have? If you aren't lop I would think those numbers are a little low for the power setting. What does the POH say for that power?

Poh says 10.5, O-470
 
Someone correct me if I am wrong but I understand that the O-470 does not have great fuel distribution and you are not advised to try running it LOP.
 
I’ve seen 100 knots TAS @ 3,000’ msl burning 4.5 gph in my 150. Once.
Your 150 goes 100 knots!! Oh, I guess mine has done that too once every blue moon. I got to make it up to your grass strip sometime soon so our 150s can chat about their fuel consumption.
 
Your 150 goes 100 knots!! Oh, I guess mine has done that too once every blue moon. I got to make it up to your grass strip sometime soon so our 150s can chat about their fuel consumption.

Come on up. The brewery is always open.
 

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First beer is on me. After that they’re free.
 

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I would still bet it’s LOP. Just because it’s carb’ed doesn’t mean it’s impossible to go LOP, just not as easy or likely. And obviously, LOP doesn’t require stumbles.

What fuel flow does the engine stumble at? Have you verified the fuel flow is accurate but checking how much you put back in the tank against what the meter is saying?
 
Well the book may indeed say 10.5gph, but it also gives a TAS of 147mph, and he's doing 135. Maybe it's LOP and/or maybe the tach or MAP are reading too high.
 
I've been getting surprisingly good fuel performance from my 182. I'm wondering if you guys are getting similar results or if there may actually be some issue.

I tend to pull back while cruising because I'm typically sight seeing. I cruise at 18" and 2300 RPM. I'm taking off at 5-6k DA and cruising between 7-11k feet MSL.

I hand calculated 9.0GPH and 11.2MPG (statute miles). I feel like that's pretty good for the average track log speed of 135MPH. This is in a stock 1963 182F without wheel pants or any mods.

I wouldn’t say that is mindblowing efficiency. I get 13-14 NMPG at 200+ KTAS dragging a bigger cabin and fixed gear through the air.
 
Well the book may indeed say 10.5gph, but it also gives a TAS of 147mph, and he's doing 135. Maybe it's LOP and/or maybe the tach or MAP are reading too high.

Ah, that's a good point. The MP and tach are both original Cessna relics.
 
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