Last spring on the trip to the Dragon ( @ 250 miles ), I got 32.3 MPG with the top down.
I have NW single CAI ( old version ), larger K&N cone filter, 74mm TB and a light foot. I did 60 on the 2 lanes, and 70 on the 4 lanes.
My UltraGuage said 35.1, but the math ( miles / gallons ) said 32.3 .

 

My SRT is right at 2000 RPM when doing 60 MPH

I drive mine maybe 3 or 4 times a week / even mix of city and highway and it is getting about 22 to23 MPG

RL

 

I feel pretty proud of myself and my '05 XFire! It's my daily driver. In town, I almost always get 315+ miles between fillups, and I often see 33 mpg on road trips without air-conditioning or 30 when using AC. Twice, on road trips, I've gotten 400+ miles between gas stops. So I guess that makes the range 25-33 mpg. Considering the fun quotient (looks, performance, compliments) I couldn't be happier!

 

400 miles between tanks???? W.O.W. I 've NEVER seen over 320 driving like miss Daisy!!

 

33mpg on 13.8 US gallons (to the warning light) = 455 miles.
Personally I do not think you can get 33mpg on a US gallon.

 

Are you saying that I am a liar, or that my math is suspect ?

To explain a bit more, it was a cool ( top up ) day, raining at points ( high humidity ) and my IAT was running 72 - 76 F.

 

I'm skipping by this on a technicality, I said I doubt you can get 33mpg not 32.3.
Ask me directly about the 32.3 and I will reply I promise.

 

I don't know about 33 but I personally got 32 on one leg of my trip to California by way of CAA 2 last year.

 

Picky, picky - ha ha.
That was just about the best reply I have ever seen - I was just jabbing at you for a response anyway, as I usually understand your sense of humor ( I should, it is identical to mine )

 

Yes, really! I just did 400 miles between fillups last month. Took a road trip from Sumter to Kiawah Island, S.C. and back again and then running around town. The "sweet spot" for my Xfire is 2400 rpm on the open road. "The Silver Bullet," as I call my Xfire, has delivered as much as 33 mpg on most of our road trips. For example, one trip I went from Sumter to W. Va. up I-95. I left here with a full tank and pulled into a gas station at that end with 405 miles on my trip odometer and about a gallon and a half left in the tank.

 

So, what's so special about your car or the way you drive it?!

 

The example is odd as it does not indicate anywhere near 33mpg.
The tank holds 15.8 US gallons, less 1.5 gallons = 14.3 gallons.
405 ÷ 14.3 = 28.18 mpg that's 15% out.

Of course I may be using your figures wrong but that's what you are saying if I take it literally.

I was running low on gas once and the low fuel lamp came on.
It took exactly 50 liters, which more or less confirmed that the tank holds 60 liters total, leaving me with 10 liters reserve rather than the 8 liters stated in the Owners Manual.
50 liters = 13.2 US gallon = 11 Imperial gallon.
60 liters = 15.8 US gallon = 13.2 Imperial gallon.

So the reserve can be safely said to be about 2 gallons (8 liters)

Info that might be useful one day.

 

Well, first leg of my trip complete. 253 miles on now quite 10 gallons. The first 40 miles was traffic jam for almost an hour then 80mph the rest of the way through. The next 120 miles was run at about 71, BUT I had an almost 30MPH head wind. The remainder was at 71 with only a slighthead wind.
Touch over 25, not terrible considering....

 

Not quite the 34 I have seen out of it, but the second leg of my trip and 2 days of city driving (150 hwy + 206 city miles) netted me 27 MPG. 12.9 gallons before I went ahead and filled her up.

 

The newly aquired 2004 Crossfire is now my commuter car. I drive 15 miles on a 55 limit 2-lane road, (with down to 35 "advised' curves, the whole thing at 60 on cruise control early in the morning, LOVE the down-shifting on cruise control downhill as needed so you don't speed up too much!) plus 25 miles of interstate freeway each way = 80 mile commute each day. this includes a 3000 foot down to sea level down elevation change & vice versa on the return.

My first full tank through the Crossfire was 26 mpg., and the 1994 Corvette LT-1 automatic it replaced got 22 in the same commute.

I will say, the Corvette got fantastic mileage for as fast as it was. I ran 13.4 @ 104.5 pretty consistantly with it on the occasional Wednesday night at the local track, and it was bone stock down to the michelin tires and factory mufflers. A retarded chimp on a crappy track would still be in the 13's with the shifter in drive and without drama. As an example, last month I got 29.1 mpg on a 300 mile trip on level freeeway travel at a constant 73 mph (1800 RPM) on cruise control and the A/C was blasting. I saw north of 30 mpg once running 60 mph though most of a tank of gas in Oregon. It weighed 3150 with a 1/3 tank of gas on the scale at the dragstrip.

The Crossfire is a HUGE leap forward in handling, (if not steering) from driving mellow all the way to the limit compared to the C4 Corvette. The Corvette handled "well" because it was very low and had huge tires, not because it had a stiff chassis. The twisty section of my commute really makes for a good comparason between vehicles, I have the road memorized. I must say, I like the Crossfire much better.

From my admittedly limited experience, and what I am reading here, it seems Crossfire will do better in my commute, better in town and hopefully tie on the freeway. The freeway cruise RPM matters.

Interestingly, my sister's 2005 M-B C320 4-matic sedan gets about the same as people report here, not any worse.

 

Well, I am still at around 220-240 miles per tank and takes right at 13.0 to 13.5 to refill, so low 16's to 18 mpg. All city and I don't have it wrapped up too often. I love my car, but it should be better. My Ram Rumble Bee had a hemi and got the same??? Doesn't make any sense. Oh well, I just drive it and try not to pay too much attention anymore to keep me from second guessing the mechanics of this car. New plugs and opened up pipes and gained a few but not much. Anyone else have suggestions? I did not change the plug wires though.......maybe in the near future, lol

 

Just for the hell of it, I tried 104+ octane booster...besides a seat-of-the-pants difference, I want to see if the mileage improves...I can only get 93 octane (R+M/2) around here...

 

A little better, shift around 3,500, cruise around 2,700 rpm. Mix of city and highway, A/C is on when the top isn't down lol.

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What type of fuel is used/recommended ? 89 or 93?
Does the tune improve fuel economy at all?

 

Any idea why it is called a "reserve" ?
On most motorcycles ( and aircraft ), the reserve is a true reserve, you have to manually move the petcock(s)/fuel selector to the reserve position.
Is this 'reserve' just the amount left after the idiot light comes on ?