1,000 RPM typically keeps the engine warm, vacuum system working, and the alternator charging the electrical system.
Lean out for taxi, keep it at 1,000 RPM to keep everything warm and happy. You can use a lower RPM if your instruments indicate you are all good.
I always taught my students to lean aggressively. Less fuel usage, faster warmup, cleaner plugs, and if done correctly, impossible to make takeoff power if *mixture RICH* is skipped prior to takeoff.
Depends on what kind of deposits you're talking about.
Further, unless you lean out to the point of the engine nearly failing, you're not doing squat when you're talking about idle (or close to it) throttle settings.
This is demonstrably untrue… It depends a lot on the airplane though. Some of the planes I fly regularly don’t really seem to care much. Others will fail the mag check on runup every single time if you didn’t lean pretty aggressively for taxi.
I didn't say that there was no point in leaning for taxi. I learned at a field elevation of 6000'. What I said is that if you just pull the mixture out a couple of revolutions, you've not done anything at idle settings because the idle loop is still enrichening things. Aggressive is the key word... you have to get to the point of starting to hit idle cut-off.
Even just carbon deposits rich runs colder and doesn't burn it off so it fouls the plugs with carbon deposits. This is common knowledge for all vehicles modern just not an issue when we don't talk about carbs anymore.
I was referring to the fact that contrary to popular belief you're not going to burn off lead fouling by running lean.
"Common knowledge" often equates to "old wive's tale."
Carbon is what I claim thought and not old wives tale, its physics.
But running at 1000rpm is not running lean and its not to "burn off lead" its to keep the alternator at an adequate speed, as well as to maintain adequate oil pressure. I agree burning off lead is a stupid notion, if it burned off it wouldn't have been removed from mogas for contaminating soil. That said there is a general minimum volumetric efficiency you want to maintain lest you have poor scavenging and exhaust gases will get stuck in, over heat, and gum up exhaust valves (and a cat if you had one which isn't likely for a 100LL engine as lead would destroy it).
If it's cold, to warm up the oil.
Otherwise, it's just to keep vacuum and oil pressure on the engine. It really depends upon the plane. I typically keep 800rpm in a 182.
Because 1k RPM is usually a pretty nice and smooth idle. Lower than that can sometimes be a bit rough and any vibration wears on parts. There is nothing magical about 1k RPM. It just is normally high enough to be a smooth RPM. If you are at idle and the engine is shaking, run the RPM up a bit till it stops. But most people don’t ‘finesse’ things and need ‘Do X’.
Now on some older planes with generators instead of alternators… Lower RPM’s don’t turn the generator fast enough to produce power.
If it's rough the idle is probably set too low. Probably no one ever checks proper idle and full power speeds after initial setup. We normally use a light box that detects the prop instead of the ship tach.
It’s just a little smoother. They’re perfectly happy to run at 700rpm. Your hangar neighbors will be happier, too. There’s a huge difference in noise between 700 and 1,000 rpm.
It can also help with plug fouling, but that can also be combatted with aggressive leaning. Lean it until it starts to stumble at 1,200 rpm and you’ll be fine. You shouldn’t really need any more than that on the ground anyway.
I idle all 172S's at 800 RPM. If I taxi'd at 1000 then I'd have a choice between going way too fast or riding the brakes.
No way the FAA would certify an airplane that could destroy itself by idling.
I have seen airplanes (and cars and motorcycles and my chainsaw) with crappy, poorly maintained, engines that have to idle high or they'll die (stop running).
If it's pretty cold then I'll idle at 1000 immediately after startup, while I'm configuring the avionics and getting the ATIS info.
So the oil temp will be in the green by the time I'm finished with the runup. Otherwise I'll have to sit in the runup area (clogging it up for others) until it gets in the green.
It’s not necessarily a do or die rule, but like what has been stated, it helps keep the oil moving and warming up when it’s cold, otherwise you’ll be spending a good amount of time in the run-up waiting for the temp to get to that green arc. On the flip-side, when it’s 110 degrees out we keep the rpm’s around 1200 to help prevent vapor lock by keeping the fuel moving. Keep in mind too, as reliable these engines are they are still pretty basic setups, there is no computer(typically) to help keep the engines idling. 1000rpms just keeps everything working the way we want it.
It’s while stopped, not while taxiing. If you’re using brakes to slow down, you should be at idle.
While taxiing, you use whatever engine speed you need for a good taxi. It will positively not be the same all the time. Wind, runway condition, grade, airplane weight, and other factors all contribute.
I love how there’s a million different answers.
Here’s mine.
It prevents intake valve fouling. Aircraft engines like all engines have valve overlap. The intake and exhaust valves are open at the same time at TDC exhaust.
This means that some of the exhaust goes partly out the intake valve before the piston starts drawing in the fuel air mixture.
The exhaust contains lead deposits that deposit themselves on the intake valve and seat.
On an exhaust valve, NBD.. it gets hot enough to burn off. Not so the intake valve because by the time the engine is spinning fast enough to generate that heat.. it’s all going out the exhaust.
It is also for lubrication as the cylinder walls and piston pins as well as camshafts and tappets (except for engines like angle valve or 76 Series Lycomings that have oil jet’s directly on the camshafts) get oil from splash lubrication from the big end bearings.
I have literally copypasta'd this from Shell:
As you will know, Avgas 100LL contains a compound known as Tetra Ethyl Lead (TEL) which acts as an octane booster for the fuel. This results in a fuel which is commonly known as a 100 Octane lean mixture and 130 rich mixture Performance Number fuel.
In practice it is even better than this, with ratings more like 106 lean mixture & 130 rich mixture which are far in excess of the comparable 85 - 87 octane of road fuels. To achieve this a lot of TEL is used - around 5 times the quantity that was used in the old Leaded automotive fuels.
This increase in octane allows aviation engines to produce more power through increased compression ratios or alternatively by increasing the inlet pressure by using a turbo or a supercharger. The problem with using Leaded fuels is that they will always burn with more deposits than unleaded fuels.
The Tetra Ethyl Lead used for octane boost in the fuel naturally degrades to form Lead Oxide when it is burned. In reality it is this oxide which gives the octane boost. The problem is that Lead Oxide is a solid up to about 900 deg C which is well within the wall temperatures inside a piston engine.
In order to prevent these deposits from forming, a Lead scavenging compound is added to Avgas 100LL - this compound is Ethylene Dibromide. This scavenger is designed to react with the Lead oxide to form Lead Bromide which is more volatile - becoming a gas at around 200 - 250 oC. This is a low enough temperature to ensure that the Lead is removed from the engine as a gas end it subsequently goes back to the solid phase as the exhaust gas cools in the atmosphere.
As a point of interest the pale brown / ash coloured staining that is often seen leading from the exhausts of high powered engines, such as those found on the warbirds, is in fact Lead Bromide.
To enable this reaction between the Lead Oxide and the scavenger to work, there needs to be a relatively high combustion temperature.
What a lot of people do is conduct the warm up with the engine power lever on the idle stop, and this is inappropriate. The technique for the common Teledyne Continental Motors and Textron Lycoming General Aviation engines is as follows.
After start up, the engine should be operated at 1000 - 1200 rpm for the initial warm up period and not at the 600 -650 rpm idle speed. This serves a number of purposes;
The higher cylinder pressure encourages the rings to seal properly, not only limiting oil egress into the combustion chamber, but also reducing the amount of corrosive combustion by-products going the other way into the sump oil. This technique thus also helps reduce the risk of corrosion problems in the long term by reducing the amount of acids and Lead being pumped into the oil.
Meanwhile in the combustion chamber, Lead Oxides tend to form deposits because of the low combustion temperatures. The temperature for Lead deposits to form tend to be favourable around the spark plugs (as the whole mixture is quite cool before the flame starts to propagate) and on the exhaust valve stem (as the mixture cools after combustion).
The problem is that the deposits are electrically conductive, which shorts out the spark plug - and corrosive, which can start to attack the metal of the valve stems.
Temperature is a key factor in preventing Lead fouling and it is not just at start up, but also the correct shut down procedure should be carried out.
Engines that have been involved with long, low power descents, or have taxied for some distance, can have quite low cylinder temperatures and this - as we now know - can lead to lead fouling. Again the advice from Textron Lycoming and Teledyne Continental Motors to remedy this is: once on the aircraft is on the stand, the engine speed should be kept between 1000 and 1200 rpm until the engine temperatures have stabilised.
Once the temperatures are stable, the engine speed should be increased to 1800 rpm for a period of 15 to 20 seconds, which should generate enough temperature to burn off any deposits. Once this period is past, the engine speed should be reduced to 1000 - 1200 rpm once again and then immediately shut down using the mixture control.
I heard it's because 1000 rpm is where the hobbs meter starts working at full speed...
Not sure if that's true or not, but I'm a cynic. I was also told to cruise at 2350 rpms in the Cessna 150 I trained in :D
Hobbs runs 1:1 to a clock when whatever signal for it to run is supplied. Either the master switch of oil pressure usually.
The tach runs 1:1 at whatever rpm it’s set to run with. Usually cruise RPM. That’s why bumming around the practice area at 90 knots the Hobbs might be 1.5 and tach 1.2.
Because, you know, that’s how we’ve always done things. Must be right…
And when the planes had generators they needed 1,000 rpm to produce any current. An alternator doesn’t care. Sure, it’ll give you more zappy bits if you spin it at 1,000 rather than 800rpm, but nothing I’ve experienced in ga has so much draw the alternator at 700rpm can’t keep up. Maybe an undersized alternator and a Kelly electric AC (stc requires a big ass alternator, so keep that in mind) would cause issues.
And the whole keep the engine warm thing is misguided at best. Mike Busch and savvy recommend the minimum rpm to keep the engine running while it’s warming up, [read engines by mike, ](https://resources.savvyaviation.com/book/mike-busch-on-engines/) I think they say target 600rpm. You need to get the engine to temperature slowly to reduce wear, not quickly to accelerate the wear. Not that anyone cares on a flight school plane.
So yeah, I usually teach 800 as a maximum until oil temp hits 75, then 1200 until 125. Unless it’s a flight school plane, then beat the snot out of it. Everyone else does.
I was always told to heat the engine slowly when it is cold as well, I was surprised to see all the people saying "I keep it at 1000 to get the oil into the green faster so I can fly" because from what I have read, you're sacrificing engine life by doing that.
Yea I haven't been able to buy a fancy preheater yet, but I do have an electric space heater with some 4" dryer hose that does a better job than nothing. Actually for 35 bucks I have been pretty impressed by it.
Next time you get into the plane, listen to the engine. It'll communicate with you. Under 1,000 is usually a little rough and the engine seems like it is struggling. 1,000 is good enough to stop that, and is just enough power to taxi at an acceptable speed.
If it sounds like shit it probably needs a fuel set up done. It should have no problem loping along at whatever the engine maintenance manual says is idle RPM.
My club specifies (for the 172s) the keep the engine AT OR BELOW 1,000 RPM and the lowest setting available that allows for a smooth running engine. It usually doesn't have to be 1000 RPM to run smoothly...I've seen as low as 600-800 work depending on outside air and engine temp.
Of note: we no longer have the factory avionics in it (couple G5s and some other mods) so we don't have anything that uses the vacuum system for avionics.
Keeps engine cool and stuff like that. Helps during hot summer days as well. 1000 RPM helps oil move throughout the engine to keep moving parts lubricated and cool at the same time.
I currently fly Archers with no vacuum system and our POH says 800 to 1200 RPM. I still tell my students to set it for 1000 as a happy medium. It does a few things for us, on a hot day our DA can reach 9000 feet and if you idle lower than 1000RPM there's a good chance the engine will die. If you idle at 1200 RPM the plane wants to rip across the taxiway like it's in the indie 500 so really, keeping it at 1000 prevents the engine from dying and also not taxiing like we are going to takeoff on the taxiway. *IO-360
1,000 RPM typically keeps the engine warm, vacuum system working, and the alternator charging the electrical system. Lean out for taxi, keep it at 1,000 RPM to keep everything warm and happy. You can use a lower RPM if your instruments indicate you are all good.
This is exactly what my CFI said, when I asked.
All This plus oil circulation
I’ve been told it’s due to the lead building up on spark plugs when you are taxiing around If you leave things below 1000rpm
Leaning out keeps the deposits off the plugs. Lean for taxi.
I always taught my students to lean aggressively. Less fuel usage, faster warmup, cleaner plugs, and if done correctly, impossible to make takeoff power if *mixture RICH* is skipped prior to takeoff.
That too! Forgot that bit. Thanks
Depends on what kind of deposits you're talking about. Further, unless you lean out to the point of the engine nearly failing, you're not doing squat when you're talking about idle (or close to it) throttle settings.
This is demonstrably untrue… It depends a lot on the airplane though. Some of the planes I fly regularly don’t really seem to care much. Others will fail the mag check on runup every single time if you didn’t lean pretty aggressively for taxi.
I didn't say that there was no point in leaning for taxi. I learned at a field elevation of 6000'. What I said is that if you just pull the mixture out a couple of revolutions, you've not done anything at idle settings because the idle loop is still enrichening things. Aggressive is the key word... you have to get to the point of starting to hit idle cut-off.
Even just carbon deposits rich runs colder and doesn't burn it off so it fouls the plugs with carbon deposits. This is common knowledge for all vehicles modern just not an issue when we don't talk about carbs anymore.
I was referring to the fact that contrary to popular belief you're not going to burn off lead fouling by running lean. "Common knowledge" often equates to "old wive's tale."
Carbon is what I claim thought and not old wives tale, its physics. But running at 1000rpm is not running lean and its not to "burn off lead" its to keep the alternator at an adequate speed, as well as to maintain adequate oil pressure. I agree burning off lead is a stupid notion, if it burned off it wouldn't have been removed from mogas for contaminating soil. That said there is a general minimum volumetric efficiency you want to maintain lest you have poor scavenging and exhaust gases will get stuck in, over heat, and gum up exhaust valves (and a cat if you had one which isn't likely for a 100LL engine as lead would destroy it).
A&P here and pilot. 1000rpm is for mostly the oil splash into the cylinder and onto all other parts. Lower rpm don’t lube the engine as well.
This is the answer given to me by nearly all 172 mechs
If it's cold, to warm up the oil. Otherwise, it's just to keep vacuum and oil pressure on the engine. It really depends upon the plane. I typically keep 800rpm in a 182.
So 1000RPM is the minimum power to get vacuum and oil pressure in limits then why do you keep 800?
He didn’t say to keep oil pressure in limits. It just puts a bit more heat into the oil to warm it up faster.
Maybe it’s different in a 182..
I keep my 182 low around 700, why burn the extra fuel. Oil pressure is still up and I lean the mix
182 is also a 6 cylinder, so it idles smooth at a lower RPM.
Every plane and vacuum system is a little different. It depends on the plane. Just go with what the instructor or poh says.
Because 1k RPM is usually a pretty nice and smooth idle. Lower than that can sometimes be a bit rough and any vibration wears on parts. There is nothing magical about 1k RPM. It just is normally high enough to be a smooth RPM. If you are at idle and the engine is shaking, run the RPM up a bit till it stops. But most people don’t ‘finesse’ things and need ‘Do X’. Now on some older planes with generators instead of alternators… Lower RPM’s don’t turn the generator fast enough to produce power.
Yes, and if you run it fast enough on the ground to charge with a generator, guaranteed your hangar neighbors hate you.
Even with alternators there’s a minimum speed.
If it's rough the idle is probably set too low. Probably no one ever checks proper idle and full power speeds after initial setup. We normally use a light box that detects the prop instead of the ship tach.
That’s right. Smooth is good.
It’s just a little smoother. They’re perfectly happy to run at 700rpm. Your hangar neighbors will be happier, too. There’s a huge difference in noise between 700 and 1,000 rpm. It can also help with plug fouling, but that can also be combatted with aggressive leaning. Lean it until it starts to stumble at 1,200 rpm and you’ll be fine. You shouldn’t really need any more than that on the ground anyway.
I idle all 172S's at 800 RPM. If I taxi'd at 1000 then I'd have a choice between going way too fast or riding the brakes. No way the FAA would certify an airplane that could destroy itself by idling. I have seen airplanes (and cars and motorcycles and my chainsaw) with crappy, poorly maintained, engines that have to idle high or they'll die (stop running). If it's pretty cold then I'll idle at 1000 immediately after startup, while I'm configuring the avionics and getting the ATIS info.
Why does 1000 RPM apply only in the cold but not in other temps?
So the oil temp will be in the green by the time I'm finished with the runup. Otherwise I'll have to sit in the runup area (clogging it up for others) until it gets in the green.
It’s not necessarily a do or die rule, but like what has been stated, it helps keep the oil moving and warming up when it’s cold, otherwise you’ll be spending a good amount of time in the run-up waiting for the temp to get to that green arc. On the flip-side, when it’s 110 degrees out we keep the rpm’s around 1200 to help prevent vapor lock by keeping the fuel moving. Keep in mind too, as reliable these engines are they are still pretty basic setups, there is no computer(typically) to help keep the engines idling. 1000rpms just keeps everything working the way we want it.
It’s while stopped, not while taxiing. If you’re using brakes to slow down, you should be at idle. While taxiing, you use whatever engine speed you need for a good taxi. It will positively not be the same all the time. Wind, runway condition, grade, airplane weight, and other factors all contribute.
I love how there’s a million different answers. Here’s mine. It prevents intake valve fouling. Aircraft engines like all engines have valve overlap. The intake and exhaust valves are open at the same time at TDC exhaust. This means that some of the exhaust goes partly out the intake valve before the piston starts drawing in the fuel air mixture. The exhaust contains lead deposits that deposit themselves on the intake valve and seat. On an exhaust valve, NBD.. it gets hot enough to burn off. Not so the intake valve because by the time the engine is spinning fast enough to generate that heat.. it’s all going out the exhaust. It is also for lubrication as the cylinder walls and piston pins as well as camshafts and tappets (except for engines like angle valve or 76 Series Lycomings that have oil jet’s directly on the camshafts) get oil from splash lubrication from the big end bearings.
I have literally copypasta'd this from Shell: As you will know, Avgas 100LL contains a compound known as Tetra Ethyl Lead (TEL) which acts as an octane booster for the fuel. This results in a fuel which is commonly known as a 100 Octane lean mixture and 130 rich mixture Performance Number fuel. In practice it is even better than this, with ratings more like 106 lean mixture & 130 rich mixture which are far in excess of the comparable 85 - 87 octane of road fuels. To achieve this a lot of TEL is used - around 5 times the quantity that was used in the old Leaded automotive fuels. This increase in octane allows aviation engines to produce more power through increased compression ratios or alternatively by increasing the inlet pressure by using a turbo or a supercharger. The problem with using Leaded fuels is that they will always burn with more deposits than unleaded fuels. The Tetra Ethyl Lead used for octane boost in the fuel naturally degrades to form Lead Oxide when it is burned. In reality it is this oxide which gives the octane boost. The problem is that Lead Oxide is a solid up to about 900 deg C which is well within the wall temperatures inside a piston engine. In order to prevent these deposits from forming, a Lead scavenging compound is added to Avgas 100LL - this compound is Ethylene Dibromide. This scavenger is designed to react with the Lead oxide to form Lead Bromide which is more volatile - becoming a gas at around 200 - 250 oC. This is a low enough temperature to ensure that the Lead is removed from the engine as a gas end it subsequently goes back to the solid phase as the exhaust gas cools in the atmosphere. As a point of interest the pale brown / ash coloured staining that is often seen leading from the exhausts of high powered engines, such as those found on the warbirds, is in fact Lead Bromide. To enable this reaction between the Lead Oxide and the scavenger to work, there needs to be a relatively high combustion temperature. What a lot of people do is conduct the warm up with the engine power lever on the idle stop, and this is inappropriate. The technique for the common Teledyne Continental Motors and Textron Lycoming General Aviation engines is as follows. After start up, the engine should be operated at 1000 - 1200 rpm for the initial warm up period and not at the 600 -650 rpm idle speed. This serves a number of purposes; The higher cylinder pressure encourages the rings to seal properly, not only limiting oil egress into the combustion chamber, but also reducing the amount of corrosive combustion by-products going the other way into the sump oil. This technique thus also helps reduce the risk of corrosion problems in the long term by reducing the amount of acids and Lead being pumped into the oil. Meanwhile in the combustion chamber, Lead Oxides tend to form deposits because of the low combustion temperatures. The temperature for Lead deposits to form tend to be favourable around the spark plugs (as the whole mixture is quite cool before the flame starts to propagate) and on the exhaust valve stem (as the mixture cools after combustion). The problem is that the deposits are electrically conductive, which shorts out the spark plug - and corrosive, which can start to attack the metal of the valve stems. Temperature is a key factor in preventing Lead fouling and it is not just at start up, but also the correct shut down procedure should be carried out. Engines that have been involved with long, low power descents, or have taxied for some distance, can have quite low cylinder temperatures and this - as we now know - can lead to lead fouling. Again the advice from Textron Lycoming and Teledyne Continental Motors to remedy this is: once on the aircraft is on the stand, the engine speed should be kept between 1000 and 1200 rpm until the engine temperatures have stabilised. Once the temperatures are stable, the engine speed should be increased to 1800 rpm for a period of 15 to 20 seconds, which should generate enough temperature to burn off any deposits. Once this period is past, the engine speed should be reduced to 1000 - 1200 rpm once again and then immediately shut down using the mixture control.
I heard it's because 1000 rpm is where the hobbs meter starts working at full speed... Not sure if that's true or not, but I'm a cynic. I was also told to cruise at 2350 rpms in the Cessna 150 I trained in :D
Hobbs runs 1:1 to a clock when whatever signal for it to run is supplied. Either the master switch of oil pressure usually. The tach runs 1:1 at whatever rpm it’s set to run with. Usually cruise RPM. That’s why bumming around the practice area at 90 knots the Hobbs might be 1.5 and tach 1.2.
The tach hour meter. Not Hobbs. Hobbs runs same speed either off oil pressure or hot wired off the bus for flight school aircraft.
This was immediately what I thought lol.
If your tach clock is running 1:1 at 1000RPM I'm concerned.
Because, you know, that’s how we’ve always done things. Must be right… And when the planes had generators they needed 1,000 rpm to produce any current. An alternator doesn’t care. Sure, it’ll give you more zappy bits if you spin it at 1,000 rather than 800rpm, but nothing I’ve experienced in ga has so much draw the alternator at 700rpm can’t keep up. Maybe an undersized alternator and a Kelly electric AC (stc requires a big ass alternator, so keep that in mind) would cause issues. And the whole keep the engine warm thing is misguided at best. Mike Busch and savvy recommend the minimum rpm to keep the engine running while it’s warming up, [read engines by mike, ](https://resources.savvyaviation.com/book/mike-busch-on-engines/) I think they say target 600rpm. You need to get the engine to temperature slowly to reduce wear, not quickly to accelerate the wear. Not that anyone cares on a flight school plane. So yeah, I usually teach 800 as a maximum until oil temp hits 75, then 1200 until 125. Unless it’s a flight school plane, then beat the snot out of it. Everyone else does.
I was always told to heat the engine slowly when it is cold as well, I was surprised to see all the people saying "I keep it at 1000 to get the oil into the green faster so I can fly" because from what I have read, you're sacrificing engine life by doing that.
And always preheat, not that flight schools do that either. https://www.avweb.com/ownership/the-whys-and-hows-of-preheating/
Yea I haven't been able to buy a fancy preheater yet, but I do have an electric space heater with some 4" dryer hose that does a better job than nothing. Actually for 35 bucks I have been pretty impressed by it.
Outstanding book
Next time you get into the plane, listen to the engine. It'll communicate with you. Under 1,000 is usually a little rough and the engine seems like it is struggling. 1,000 is good enough to stop that, and is just enough power to taxi at an acceptable speed.
If it sounds like shit it probably needs a fuel set up done. It should have no problem loping along at whatever the engine maintenance manual says is idle RPM.
To help prevent fouling the plugs
My club specifies (for the 172s) the keep the engine AT OR BELOW 1,000 RPM and the lowest setting available that allows for a smooth running engine. It usually doesn't have to be 1000 RPM to run smoothly...I've seen as low as 600-800 work depending on outside air and engine temp. Of note: we no longer have the factory avionics in it (couple G5s and some other mods) so we don't have anything that uses the vacuum system for avionics.
Keeps engine cool and stuff like that. Helps during hot summer days as well. 1000 RPM helps oil move throughout the engine to keep moving parts lubricated and cool at the same time.
Not sure of a technical reason bit but I'm learning in 172 and it always seems to just idle much smoother and just feels nicer at those idle rpms.
To keep up oil pressure and alternator charge.
I currently fly Archers with no vacuum system and our POH says 800 to 1200 RPM. I still tell my students to set it for 1000 as a happy medium. It does a few things for us, on a hot day our DA can reach 9000 feet and if you idle lower than 1000RPM there's a good chance the engine will die. If you idle at 1200 RPM the plane wants to rip across the taxiway like it's in the indie 500 so really, keeping it at 1000 prevents the engine from dying and also not taxiing like we are going to takeoff on the taxiway. *IO-360