Have been doing some long range flying with the 182 the past week. I have been getting about 14.2 gph running 23 squared. Running around at about 6k with climbs at 24 squared. I have been leaning but I just have one single point EGT on the bottom of one collector. I thought l would see much lower fuel burn at 23 23. When leaning It seems pulling the mix anything more then about 1/2" causes power loss or rough runner. I really wish I had multi point EGT. Leaning for a slight drop in power and pushing it back in a bit method.
Is anything less then 14 gph obtainable at 23 and 4-6k altitude?

I think you can do better. We had a '56 converted 182 once upon a time and typically saw 12.5 gph flying around southcentral Ak at 23 "square". You should check for an induction system leak where you might be getting a lean mixture on one cylinder before the rest peak. We had an issue with one cylinder after major overhaul and experienced some of the symptoms you are describing.

PAMR MX wrote:Have been doing some long range flying with the 182 the past week. I have been getting about 14.2 gph running 23 squared.
Is anything less then 14 gph obtainable at 23 and 4-6k altitude?

That's really bad. I have a 520 on the Bonanza and 23 squared is one of the settings I use. That is 65% and I go right to 12.5 GPH. Maybe you have some air leaks in your induction system.

PAMR MX wrote:Have been doing some long range flying with the 182 the past week. I have been getting about 14.2 gph running 23 squared. Running around at about 6k with climbs at 24 squared. I have been leaning but I just have one single point EGT on the bottom of one collector. I thought l would see much lower fuel burn at 23 23. When leaning It seems pulling the mix anything more then about 1/2" causes power loss or rough runner. I really wish I had multi point EGT. Leaning for a slight drop in power and pushing it back in a bit method.
Is anything less then 14 gph obtainable at 23 and 4-6k altitude?

Are you figuring the 14.2 or is it a flow indicator?
you should be at about 12gph

At 6k', I estimate 12.5 gph at 2300 and wide open (22"). I only use that for climbing though...I hardly ever use that for cruise since a 5-7 mph sacrifice in speed puts fuel flow down to 11.2, and 10-12 mph puts it safely at 10.2-ish.

My vac leak issues were easy to nail down by flying down lower and looking at how it leaned at 15" versus 20-21". With the leak, roughness was early and a couple egts were really leading the pack while loping around at 15". Afterwards, the egts became more even than at higher MP and the roughness was delayed and much less vague (multiple jugs reaching lean condition at same time).

The 182 '73P 0-470R that I fly gets better than that. At low density Altitudes (2000-5000) at 22 squared (below 65% power) it is no problem to get down to the high 11's on the fuel flow. I have all 6 cycliders monitored with EGT and CHT. The CHtemps are all well below 350 deg with no roughness.

Macdon221

I have been figuring burn by topping off the tanks and going off my flight timer on my digital EI tach.
I had 14.3 Merrill to Yakutat.
14.39 Yakutat Haines Skagway juneau. I still need to fill up in Wrangell but it's probably worse since I had carb heat on the whole flight.
I will check for some induction leaks this evening if the rain does not return.

PAMR MX wrote:I have been figuring burn by topping off the tanks and going off my flight timer on my digital EI tach.
I had 14.3 Merrill to Yakutat.
14.39 Yakutat Haines Skagway juneau. I still need to fill up in Wrangell but it's probably worse since I had carb heat on the whole flight.
I will check for some induction leaks this evening if the rain does not return.

It will be interesting to hear your fuel burn on that last leg as some recommend carb heat for better atomization of fuel allowing for leaner operations.

Opinions vary of course, but after owning 3 C180's over the last 20 years, that seems like totally normal fuel burn to me. Of course I always have the slowest, biggest piece of crap gas hog airplane, poorest shooting rifle, and the dumbest dog.

That seems about right to me. I figure 12 for flight planning, but I'm 10-12k at cruise, 20-22 inches and 2300 on the prop. Fuel is cheap compared to engine work, I'm 300 hours away from TBO with no issues yet. I know too many pilots that get better mileage but ruin engines.

I have an O-470S (same as an R, but with piston oil squirters) in the 180.

I too have the crappy single point EGT probe that takes forever to react. Leaning is probably a 10 minute process to find the true peak, then lean to 20 LOP. It really takes a lot of patience to get it right.

Using that, I was averaging 10.8 GPH at 7500, 10.2-10.3 at 9500, and 10 or just below at 10,500'. Those are leg averages (fuel added/flight time) since I don't have any fuel flow info in the panel yet.

gbflyer wrote:Opinions vary of course, but after owning 3 C180's over the last 20 years, that seems like totally normal fuel burn to me. Of course I always have the slowest, biggest piece of crap gas hog airplane, poorest shooting rifle, and the dumbest dog.

That's a hysterical way to explain bad luck. My sympathies

gbflyer wrote:Opinions vary of course, but after owning 3 C180's over the last 20 years, that seems like totally normal fuel burn to me. Of course I always have the slowest, biggest piece of crap gas hog airplane, poorest shooting rifle, and the dumbest dog.

Haha. Sounds like we've owned a lot of the same stuff.

I have an O470R in my 180. I lean till slight roughness then 3 twists in on the vernier. About 12.5 gph at 23 squared on my fuel flow meter.

All 3 0-470's I've owned (L,R,U) will burn about 9.5-10gph at 23/2300 LOP. I lean till stumble then in till smooth, let everything stabilize and lean another 2-3 turns out or so for desired CHT. Graphic engine analyzer/fuel flow is a good idea IMO if trying to lean for best fuel economy, among other reasons. At 23 square with bushwheels I cruise about 140-150mph ground speed depending on altitude. If your timing is not right you won't be able to run LOP, also as others said induction should be checked. Clean and properly gapped spark plugs are necessary to run lean as well, I get about 40-50 hours max before needing to clean again for smooth operation. Obviously some engines run lean better than others and my current U motor requires more technique than the L or R did. Experiment with throttle settings and partial carb heat to help more evenly distribute fuel flow. My EGTs all stay within 30-50 deg and CHTs are usually within 30 degrees overall and 10 degrees between opposing cylinders. Engine runs way cooler lean than rich.

The 0 470L/R will run fine at 2300 rpm/21 inches leaned out to about 10-11 gph . That's about 67% which gives about 153 mph True.

marcusofcotton wrote:

PAMR MX wrote:I have been figuring burn by topping off the tanks and going off my flight timer on my digital EI tach.
I had 14.3 Merrill to Yakutat.
14.39 Yakutat Haines Skagway juneau. I still need to fill up in Wrangell but it's probably worse since I had carb heat on the whole flight.
I will check for some induction leaks this evening if the rain does not return.

It will be interesting to hear your fuel burn on that last leg as some recommend carb heat for better atomization of fuel allowing for leaner operations.

See if you can find a 180 driver from the 180/185 club. There was a really smart guy who wrote some tech articles for them many moons ago on using carb heat for better cruise fuel consumption. I'm a 185 guy, so I never dug into them, but I remember my dad talking about it.

Thanks for all the help.
I got the cowl off in this monsoon of a rain storm and found loose intake clamps right away. Almost all of them we're loose. One hose clamp on the Y pipe was totally off and just dangling. One double clamp on the fwd crossover was so warped and bent that it was not sealing at all. That one had a pretty big fuel leak. The y pipe hose probably had an 1/8" gap or more. Lots of leakage!
It will be interesting to see how much economy boost it gives. I know for sure it's going to be a heck of a lot smoother.
Will give a report of the change in GPH.

It's been a long time since I owned in partnership a 182, but I recall using 14 gph for flight planning, to be conservative, but actually getting about 12.5 on long cross countries, like more than 1000 miles with a couple fuel stops. That was at full throttle and 2400 rpm, at 11 or 12,000' most of the time. I think full throttle was around 19" or so, though, at those altitudes. We didn't have any sophisticated instruments to help with the leaning, so it was lean till rough, then enrichen a bit. I also flight planned for 130 knots, though the airplane would go a bit faster at cruise. It all worked out pretty well.

Cary

Cary wrote:It's been a long time since I owned in partnership a 182, but I recall using 14 gph for flight planning, to be conservative, but actually getting about 12.5 on long cross countries, like more than 1000 miles with a couple fuel stops. That was at full throttle and 2400 rpm, at 11 or 12,000' most of the time. I think full throttle was around 19" or so, though, at those altitudes. We didn't have any sophisticated instruments to help with the leaning, so it was lean till rough, then enrichen a bit. I also flight planned for 130 knots, though the airplane would go a bit faster at cruise. It all worked out pretty well.

Cary

That's pretty similar to my world. I can get 10 by myself in the Winter but can't plan that way, I burned both tanks out racing thunderstorms back from the Oregon coast hauling two lardasses and a bunch of halibut balls to the wall at 7.5. Got a whopping 15.5 gph Also owned the dumbest dog for 8 years- a Chesapeake.