408 gas mileage? Hmm.
11-29-2005, 11:02 PM
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408 gas mileage? Hmm. Yeah, I realize those the two (408 & mpg) should never be used in the same sentence. However, I can't help but wonder about something. I've now got several hundred miles on the motor and have been paying real close attention to the fuel mileage. Not for any particular reason than curiousity, really.
Cam is a 244/248 .612/.615 115lsa. Rear gear is 3.23 w/ A4 tranny. 3500 stall converter.
City driving, regardless of using 3rd or 4th... 11 mpg.
On the interstate, avg. 70mph in 4th... 17.5 mpg (perfectly flat ground).
With the stock setup I saw 19mpg in the city, and 27 on the highway.
Just wondering if the rest of you who've paid attention have noticed similar drops in mpg? Obviously with a car making more than 200 crank hp over stock it's going to drink some fuel. I'm not complaining. Just real curious as to what the rest of ya have seen - especially you guys with A4s!!
Cam is a 244/248 .612/.615 115lsa. Rear gear is 3.23 w/ A4 tranny. 3500 stall converter.
City driving, regardless of using 3rd or 4th... 11 mpg.
On the interstate, avg. 70mph in 4th... 17.5 mpg (perfectly flat ground).
With the stock setup I saw 19mpg in the city, and 27 on the highway.
Just wondering if the rest of you who've paid attention have noticed similar drops in mpg? Obviously with a car making more than 200 crank hp over stock it's going to drink some fuel. I'm not complaining. Just real curious as to what the rest of ya have seen - especially you guys with A4s!!
11-30-2005, 08:24 AM
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Have you retuned the pcm since the 408 swap? running closed or open loop ect?
408 238/242 xer a4 c5 coupe 3.42 ss3800 c5 80 mph 23mpg
11-30-2005, 08:41 AM
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Originally Posted by 408LS1TA
Yup! I had it tuned by Speed Inc in Schaumburg IL. As far as open or closed loop, I have no idea. Is there an easy way to go about finding this out? I have a laptop and an OBD2 cable / software for monitoring things.
That is incredible! Maybe I need a C5 instead of a T/A. haha!
That is incredible! Maybe I need a C5 instead of a T/A. haha!
11-30-2005, 09:52 AM
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I have owned my 98 A4 TA with 3.23 gears since it was almost new and have never gotten 27 mpg on the hwy.
FWIW - My new LS2 402 is an A4 with a Strange 12-bolt and 3.73 gears which averaged 16-17 mpgs between the city and hwy when breaking in the motor for the first 250 miles. I also run a TCI 3800 converter with a 244/250 113 lsa cam.
The car is running rich (-10 LTFT's) and still needs to be tuned further.
FWIW - My new LS2 402 is an A4 with a Strange 12-bolt and 3.73 gears which averaged 16-17 mpgs between the city and hwy when breaking in the motor for the first 250 miles. I also run a TCI 3800 converter with a 244/250 113 lsa cam.
The car is running rich (-10 LTFT's) and still needs to be tuned further.
