APR/Revo fuel economy
01-09-2012, 03:19 PM
#11
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[QUOTE=LeoR604;24245822With the Revo tune seemingly running a lower AFR, I am wondering if the fuel mileage will be impacted. Also looking forward to logs of APR V2 to see if AFR's have changed. [/QUOTE]
Fuel mileage will not be affected. If you set the cruise at 70 mph you will (for all intents and purposes) get the same mileage.
if you have your foot in it, you will get worse.
When we do see logs of APR vs #2 tune, it won't matter for mileage. Any logs we see will be at WOT, and thus not affecting cruise and low throttle AFRs.
Fuel mileage will not be affected. If you set the cruise at 70 mph you will (for all intents and purposes) get the same mileage.
if you have your foot in it, you will get worse.
When we do see logs of APR vs #2 tune, it won't matter for mileage. Any logs we see will be at WOT, and thus not affecting cruise and low throttle AFRs.
01-09-2012, 03:49 PM
#13
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It's been discussed here, on Audizine and on QW many times, there are not only speculations but also pictures of cars (mine included) with anywhere from 7K to 18K miles if I recall. No new information, so I'm not going to rehash what can be easily searched. While certainly not anywhere near RS4 proportions, there is carbon on the intake valve backing on all pics. How fast it builds up, based on what conditions (temps, driving characteristics, fuel, etc), and if it stops after a certain point all remain to be seen.
01-09-2012, 05:22 PM
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[QUOTE=LeoR604;24245822With the Revo tune seemingly running a lower AFR, I am wondering if the fuel mileage will be impacted. Also looking forward to logs of APR V2 to see if AFR's have changed. [/QUOTE]
Fuel mileage will not be affected. If you set the cruise at 70 mph you will (for all intents and purposes) get the same mileage.
if you have your foot in it, you will get worse.
When we do see logs of APR vs #2 tune, it won't matter for mileage. Any logs we see will be at WOT, and thus not affecting cruise and low throttle AFRs.
Fuel mileage will not be affected. If you set the cruise at 70 mph you will (for all intents and purposes) get the same mileage.
if you have your foot in it, you will get worse.
When we do see logs of APR vs #2 tune, it won't matter for mileage. Any logs we see will be at WOT, and thus not affecting cruise and low throttle AFRs.
01-09-2012, 05:42 PM
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Fuel mileage will not be affected. If you set the cruise at 70 mph you will (for all intents and purposes) get the same mileage.
if you have your foot in it, you will get worse.
When we do see logs of APR vs #2 tune, it won't matter for mileage. Any logs we see will be at WOT, and thus not affecting cruise and low throttle AFRs.
if you have your foot in it, you will get worse.
When we do see logs of APR vs #2 tune, it won't matter for mileage. Any logs we see will be at WOT, and thus not affecting cruise and low throttle AFRs.
the amount of work isn't commensurate with the amount of fuel burned. Don't forget the pistons are moved by an explosion that is caused by a mixture of fuel and air being ignited. If there is a little excess fuel as in a stock tune (vs. optimal power making ratio) and you trim it out running a leaner-than-stock mixture (but not lean per se) you're going to make power with less fuel...or with the same fuel, make more power. But to reiterate a confusing post, the explosion is not necessarily more powerful because there is more fuel...nor is it less powerful if there is less fuel. It's air fuel + ignition = boom = piston forced down = crank turned = power and work getting done.
The difference can be pretty big in fact.
Last edited by sakimano; 01-09-2012 at 05:45 PM.
01-10-2012, 04:17 PM
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how do you figure? I mean I'm not saying it's a huge difference going from a rich stock tune to a more optimal-for-power AFR tune...but how do you figure that it's the same?
the amount of work isn't commensurate with the amount of fuel burned. Don't forget the pistons are moved by an explosion that is caused by a mixture of fuel and air being ignited. If there is a little excess fuel as in a stock tune (vs. optimal power making ratio) and you trim it out running a leaner-than-stock mixture (but not lean per se) you're going to make power with less fuel...or with the same fuel, make more power. But to reiterate a confusing post, the explosion is not necessarily more powerful because there is more fuel...nor is it less powerful if there is less fuel. It's air fuel + ignition = boom = piston forced down = crank turned = power and work getting done.
The difference can be pretty big in fact.
the amount of work isn't commensurate with the amount of fuel burned. Don't forget the pistons are moved by an explosion that is caused by a mixture of fuel and air being ignited. If there is a little excess fuel as in a stock tune (vs. optimal power making ratio) and you trim it out running a leaner-than-stock mixture (but not lean per se) you're going to make power with less fuel...or with the same fuel, make more power. But to reiterate a confusing post, the explosion is not necessarily more powerful because there is more fuel...nor is it less powerful if there is less fuel. It's air fuel + ignition = boom = piston forced down = crank turned = power and work getting done.
The difference can be pretty big in fact.
I am sorry, I am not here much, and I can't write 10 paragraphs. I have been tuning cars for a while, and some of my buddies tune Audi's (though as of yet I do not). I have a decent idea of what I am talking about.
The tune is not richer, it is richer in certain areas, like WOT or say above 10 psi or so (just guessing here, but I am likely close). The areas use use 99% of the time will likely run the same AFR as stock, thus getting pretty much exactly the same mileage as stock.
01-10-2012, 04:26 PM
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My posts don't show up in order, so I am not sure what is going here.
At anyrate, someone asked:
You are correct. This has very little to do with the thread's topic about fuel economy, as I assume he means when the car is driven in a sane manner.
But when you are using the new-found power at WOT, or at least aggressive throttle useage, you have valid points, but are missing some pieces of the puzzle.
If you just go richer, you will likely lose power. This assumes that you consider the APR tune at 12:1 or so to be normal, and the REVO tune at 11:1 to be rich. Most engines make best power on gasoline at about 12 - 12.5:1 AFR.
Why not just lean it out then to make more power? Simple, we will get detonation, there-fore we use extra fuel to cool the mixture to ward of det.
With any engine, fuel, weather conditions, etc... there is a sweet spot of going richer to ward of det, and adding timing to get more power (running less then optimal timing has a HUGE impact on power, a lot more then AFR does). On pretty much any forced induction car on anything less then pump gas or E85, we have to run less then optimal timing or else we get detonation. Therefore different tuners will enrich things a certain degree to cool enough for the timing the wish to run.
I will also re-iterate my previous point:
When you are driving along like a normal person you r car is running pretty close to 14.7:1 regardless of tune (APR, stock, REVO).
At anyrate, someone asked:
he amount of work isn't commensurate with the amount of fuel burned. Don't forget the pistons are moved by an explosion that is caused by a mixture of fuel and air being ignited. If there is a little excess fuel as in a stock tune (vs. optimal power making ratio) and you trim it out running a leaner-than-stock mixture (but not lean per se) you're going to make power with less fuel...or with the same fuel, make more power. But to reiterate a confusing post, the explosion is not necessarily more powerful because there is more fuel...nor is it less powerful if there is less fuel. It's air fuel + ignition = boom = piston forced down = crank turned = power and work getting done.
But when you are using the new-found power at WOT, or at least aggressive throttle useage, you have valid points, but are missing some pieces of the puzzle.
If you just go richer, you will likely lose power. This assumes that you consider the APR tune at 12:1 or so to be normal, and the REVO tune at 11:1 to be rich. Most engines make best power on gasoline at about 12 - 12.5:1 AFR.
Why not just lean it out then to make more power? Simple, we will get detonation, there-fore we use extra fuel to cool the mixture to ward of det.
With any engine, fuel, weather conditions, etc... there is a sweet spot of going richer to ward of det, and adding timing to get more power (running less then optimal timing has a HUGE impact on power, a lot more then AFR does). On pretty much any forced induction car on anything less then pump gas or E85, we have to run less then optimal timing or else we get detonation. Therefore different tuners will enrich things a certain degree to cool enough for the timing the wish to run.
I will also re-iterate my previous point:
When you are driving along like a normal person you r car is running pretty close to 14.7:1 regardless of tune (APR, stock, REVO).
01-10-2012, 06:06 PM
#18
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I don't want some unexpected big hit on daily mileage and, as several have mentioned, the uncertainty of what a rich mixture is doing in regards to carbon buildup and emissions. I like a well balanced approach rather than focusing ONLY on power.
In my mind, leaner is cleaner both at the valves (blowback) and out the tailpipe. If all tunes are running close to the stoichiometric ratio under *normal* driving conditions, then they will probably all be very similar in fuel economy, emissions and possible carbon buildup.
Keep the data coming (GIAC users, too).
01-11-2012, 06:26 AM
#19
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Go into your settings, you can choose threaded message view, or the default. Threaded works if people hit the reply button to YOUR post they are replying to, but many just hit quote or reply to the end of the thread which breaks the way things post here for some people's view.
01-11-2012, 07:34 AM
#20
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to the OP...
Different engine,
but in the wife's 2.0T in the Q5 mpg has been better even WITH spirited driving so far...
here is a pic a week after tuning of our around town mpg:
https://www.audiworld.com/forums/alb...ctureid=234605
I might add the previous 4 or 5 cars I've tuned, gas and diesel, in EVERY case the mpg went up when driven the same...
Not enough to pay for the tune/programmer, but a nice by-product of the tuning.
Different engine,
but in the wife's 2.0T in the Q5 mpg has been better even WITH spirited driving so far...
here is a pic a week after tuning of our around town mpg:
https://www.audiworld.com/forums/alb...ctureid=234605
I might add the previous 4 or 5 cars I've tuned, gas and diesel, in EVERY case the mpg went up when driven the same...
Not enough to pay for the tune/programmer, but a nice by-product of the tuning.