I dunno if this is advice or not, but it was an entertaining tale to tell....

https://www.northamericanmotoring.co...-hard-way.html

Kind regards,

Charlie

 

Wow Charlie: Great read! 35 MPG? Must be the tune. I bought the Mini-Madness Stage II (Advertised 215 HP) including Evotech software, but without the exhaust. I have read that cat-back exhaust only adds about 5-10 HP, and very little at mid-range RPM where I do most driving.

Mileage is same since mods and tune as before - maybe a little better. Obviously, 380cc injectors wouldn't lower mileage, since you have those.

--Russ

 

'02-'03 ECMs tend to be overly optimistic about mileage. '05-06' ECMs tend to be overly pessimistic. Don't recall how the '04 ECM is. Not that I don't believe 35 MPG. The tune in my old '02 MCS did improve mileage a little, though, even if it was reading higher than the actual amount. Always the best way is to use your trip per tank and divide by gallons at next fillup.

The opinion by many is your mileage tends to go down when you do mods because you're more foot happy. Yours truly included. For most non-boost regular driving conditions, your MPG should be at least the same, if not slightly higher, with a good tune.

 

My car is rated 21 city 29 Hwy after adjusting for new EPA. I keep fairly good track (miles driven divided by gas purchased) and actually got 29 on 5K trip to Indiana and back driving 75-85 MPH, and I average 26 all the time - living in town driving about 35-40 MPH. I do drive conservatively - low RPM - 2,000 - 3,000 except when I want to have some fun on back roads. So, over-all, I can't complain. Maybe the Cabrio design is less slippery and takes more gas at higher speed. So, it's hard to believe 35 MPG from heavily modded cars.

To me this car is a really fine automobile now, after all the mods. But if there is a little more power to be had without destroying the smooth linear power and other fine characteristics, I'm interested. The only three things I can think of now are: Borla STREET catback exhaust, (not too loud?) Helix13 380cc quad-cone injectors, (better spray pattern) and maybe the right street cam. As I said before, I'm a bit afraid of DT BPV - not sure I want to risk it. (They advertise one more pound of boost due to better closing.) I think the OEM BPV is pretty much closing fully or nearly so, and it seems to have smooth spring action when I push on it.

--Russ

Mods: Mini-Madness Stage II package (except exhaust), ALTA (TB) Inlet tube, DOS copper IC, Koni FSD shocks/struts, Madness upper and lower bar/braces, Madness 22mm rear anti-sway, Power steering fan enclosed duct, Madness shock tower plates, and longer strut plate studs.