Better MPG's w/ Main Cat vs. MP/Hi-Perf Cat Conv. combo
#1
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Better MPG's w/ Main Cat vs. MP/Hi-Perf Cat Conv. combo
I took the MP/Cat Conv. off last month and replaced it with a Main Cat that had less than 30K miles. Kept the DP on.
Average city MPG with Mid pipe/Hi-Performance Magnaflow Cat Converter was 15.0. Average highway MPG with MP was 22.0
Average city MPG with stock Main-Cat is now 20.4. Pretty good number I think.
Fuel Octane: 93
Reman with 28.5K current miles. (Installed on 01/01)
PROS: Main Cat has added 5.4 mpg in city driving. Dbs much, much lower. Although still loud at WOT. Pretty pleasant over 3K rpm. Don't have any mpg numbers for highway driving, but I intent to take her out of town tomorrow. Hope I can approach 28mpg.
CONS: Notable HP loss (10-20?) at WOT.
But car still has great top-end speed. Had her up to 152 MPH last week with a little more to give
Just thought I'd share the info with y'all.
Average city MPG with Mid pipe/Hi-Performance Magnaflow Cat Converter was 15.0. Average highway MPG with MP was 22.0
Average city MPG with stock Main-Cat is now 20.4. Pretty good number I think.
Fuel Octane: 93
Reman with 28.5K current miles. (Installed on 01/01)
PROS: Main Cat has added 5.4 mpg in city driving. Dbs much, much lower. Although still loud at WOT. Pretty pleasant over 3K rpm. Don't have any mpg numbers for highway driving, but I intent to take her out of town tomorrow. Hope I can approach 28mpg.
CONS: Notable HP loss (10-20?) at WOT.
But car still has great top-end speed. Had her up to 152 MPH last week with a little more to give
Just thought I'd share the info with y'all.
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There is NO way that adding a restriction to the exhaust nets a fuel mileage increase, let alone of the order of magnitude you are claiming. Sorry, but you either miscalculated it or there is something else responsible for the change.
#3
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Originally Posted by rynberg
There is NO way that adding a restriction to the exhaust nets a fuel mileage increase, let alone of the order of magnitude you are claiming. Sorry, but you either miscalculated it or there is something else responsible for the change.
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Originally Posted by rynberg
There is NO way that adding a restriction to the exhaust nets a fuel mileage increase, let alone of the order of magnitude you are claiming. Sorry, but you either miscalculated it or there is something else responsible for the change.
#6
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Originally Posted by ulost2my7
i dont know about this one
why do you think when a manufacturer puts out a car, it has the most restrictive exhaust ever? to pass emissions and at the same time get better fuel economy..
why do you think when a manufacturer puts out a car, it has the most restrictive exhaust ever? to pass emissions and at the same time get better fuel economy..
I second that notation. At first I thought it was hard to believe, but you also got to take in account the fact of running less boost (less full tossed in engine) with a more restrictive exhaust.
What I would question more and what to know is how are you getting such a high MPG in the city? Whats your driving habits, setup, etc..... Fill us in, any ting to squeeze a few more mpg is gold!
#7
In general, restriction wastes fuel. But there are a lot of other things going with engine control systems, etc. that could negate the savings.
I do find it hard to believe that you got >20 MPG in city driving with this car. What is your method for measuring MPG?
-Max
I do find it hard to believe that you got >20 MPG in city driving with this car. What is your method for measuring MPG?
-Max
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Originally Posted by areXseven
WAY!!!. I've been documenting MPG since acquiring the FD in 05/03. The numbers are accurate.
I would think that more restriction = less boost = less fuel = better MPG
It's simple physics.
#10
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Originally Posted by eyecandy
I second that notation. At first I thought it was hard to believe, but you also got to take in account the fact of running less boost (less full tossed in engine) with a more restrictive exhaust.
What I would question more and what to know is how are you getting such a high MPG in the city? Whats your driving habits, setup, etc..... Fill us in, any ting to squeeze a few more mpg is gold!
What I would question more and what to know is how are you getting such a high MPG in the city? Whats your driving habits, setup, etc..... Fill us in, any ting to squeeze a few more mpg is gold!
Originally Posted by maxcooper
In general, restriction wastes fuel. But there are a lot of other things going with engine control systems, etc. that could negate the savings.
I do find it hard to believe that you got >20 MPG in city driving with this car. What is your method for measuring MPG?
-Max
I do find it hard to believe that you got >20 MPG in city driving with this car. What is your method for measuring MPG?
-Max
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Originally Posted by rynberg
No, I don't believe they are.
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Originally Posted by rynberg
There is no way someone is getting over 3 mpg better than the EPA estimate for city driving, not in this car.
#13
the best MPG I've ever gotten HIGHWAY, hardly boosting if ever, (DP and catback) was 24mpg... going between 70-80mph... (on the way to Mid-Ohio Sportscar Course)...
I'm really amazed that you're hitting over 20mpg city, though... taking it really easy, the best I've seen city is about 19mpg...
when just driving normally, though, we're talking about 17mpg....
I'm really amazed that you're hitting over 20mpg city, though... taking it really easy, the best I've seen city is about 19mpg...
when just driving normally, though, we're talking about 17mpg....
#14
I'm still curious about your method for calculating MPG. Perhaps there is some issue with the method that is skewing the results. Please describe your method.
If I could get 15 MPG city, I'd be pretty happy. Or bored.
-Max
If I could get 15 MPG city, I'd be pretty happy. Or bored.
-Max
#16
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Originally Posted by maxcooper
I'm still curious about your method for calculating MPG.
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Originally Posted by maxcooper
I'm still curious about your method for calculating MPG. Perhaps there is some issue with the method that is skewing the results. Please describe your method.
If I could get 15 MPG city, I'd be pretty happy. Or bored.
-Max
If I could get 15 MPG city, I'd be pretty happy. Or bored.
-Max
Method: I ALWAYS fill with ten (10) gallons and wait till low fuel light comes on. I mark mileage on my trip odometer and devide by ten. Since the Main-Cat install I've been averaging 204 miles per 10 gallons of 93 octane fuel. I was averaging 150 miles per 10 gallons when the MP/ hi-perf cat was on.
But I will add (just realized) that I installed new rubber all around (Dunlop FM901 P235/ZR40-17s) at the same time I installed the main-cat. Hmmmmm??.
The new tires are the same size as the old (Yoko A520's) ones.
Last edited by areXseven; 01-28-05 at 10:43 PM.
#18
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Originally Posted by areXseven
But I will add (just realized) that I installed new rubber all around (Dunlop FM901 P235/ZR40-17s) at the same time I installed the main-cat. Hmmmmm??.
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Originally Posted by Kento
If those Dunlops are different in any way from the tires you had previously, that will skew the results.
#20
2/4 wheel cornering fiend
Originally Posted by areXseven
Definitely a softer, quiter ride. Grips like a ***** though
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Originally Posted by Kento
What I meant was that whether you had the exact same Dunlops on your car previously...
Last edited by areXseven; 01-28-05 at 10:51 PM.
#23
2/4 wheel cornering fiend
Originally Posted by areXseven
I had Yoko A520s. Different tire manufacturer, but same size.
#24
Super Snuggles
Originally Posted by areXseven
Method: I ALWAYS fill with ten (10) gallons and wait till low fuel light comes on. I mark mileage on my trip odometer and devide by ten.
The gas gauge and sensor are not incredibly accurate. It's far more accurate to let the gas pump do the calculating of how much fuel has been consumed.
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Originally Posted by patriick
What ECU? Airpump?