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Just purchased my '06 C55 and besides the rough idle I'm getting horrible gas mileage. What are you guys seeing mpg wise? Any suggestions on what to do maintenance wise to squeeze out a few more miles to the tank?
That is 1950's logic right there. Displacement is one of maybe 10 things that determine mpg(and OP hasn't clarified what "horrible" is).
Fun is #2 or 3 on my priority list for my next car, mpg... not so much. However, it will be my DD so I still have what I consider an acceptable range and have written a few cars off because of that. My top 2 cars right now are the C55 and 05/06 GTO.
A 5 speed auto, 5.4L C55 is rated 16/22. A 6 speed manual, 6.0L GTO is rated 17/25. This, all the while the GTO weighs over 150lbs more, .3L more displacement, nearly 40 more hp, has a 3.46 rear VS 3.06, a cd of .31 vs .27, and the C55 has twin spark plugs for a more complete burn. The LSx engines are also notorious for beating their ratings when not driven like a mad man.
Why? The main reason is despite the 3.46 VS 3.06 rears, 6th gear in the GTO is .57 VS the C55's .83. It's a huge difference real world, while the C55 is turning 2414rpm's at 70mph the GTO is turning 1826. Have I ruled out the AMG because of that? Certainly not. A test drive back to back when I'm ready to buy will decide that, and my commute to work is
Last edited by ///AchMeinGott; 07-16-2015 at 06:59 PM.
Reason: Didn't post full message?
That is 1950's logic right there. Displacement is one of maybe 10 things that determine mpg(and OP hasn't clarified what "horrible" is).
Fun is #2 or 3 on my priority list for my next car, mpg... not so much. However, it will be my DD so I still have what I consider an acceptable range and have written a few cars off because of that. My top 2 cars right now are the C55 and 05/06 GTO.
A 5 speed auto, 5.4L C55 is rated 16/22. A 6 speed manual, 6.0L GTO is rated 17/25. This, all the while the GTO weighs over 150lbs more, .3L more displacement, nearly 40 more hp, has a 3.46 rear VS 3.06, a cd of .31 vs .27, and the C55 has twin spark plugs for a more complete burn. The LSx engines are also notorious for beating their ratings when not driven like a mad man.
Why? The main reason is despite the 3.46 VS 3.06 rears, 6th gear in the GTO is .57 VS the C55's .83. It's a huge difference real world, while the C55 is turning 2414rpm's at 70mph the GTO is turning 1826. Have I ruled out the AMG because of that? Certainly not. A test drive back to back when I'm ready to buy will decide that, and my commute to work is
Performance aside, how do you like the exterior styling of the GTO compared with the C55?
Wouldn't post my full comment even after I restarted my phone, anybody know why that might be?
Originally Posted by mtownerman
Performance aside, how do you like the exterior styling of the GTO compared with the C55?
I think both fall into a certain class. Some Ford/Dodge fanbois call the GTO ugly. I genuinely think there isn't anything one could consider offensive about the car. Boring? Mostly. Ugly? Of course not, it's styling is totally cohesive. I think the C55 is the same. There was one near my folks place in South Carolina, so I asked them to stop by, see what they thought(not to buy, it was high mileage, but to see how it held up). My dad said beyond the lip spoiler nothing stuck out to him. It's certainly understated, but no sain person can call a w203 ugly. There are little body mods to do to the GTO though to spice it up, in the right color, it even looks classy. The C, probably just put a blacked out/chrome star grill and be done. Interior, the C has a bit better quality and looks clean, but the GTO has multiple color matched interiors and some of the most comfy seats ever. I personally like loud, in your face cars usually, but these two seem to fit my requirements best.
Wouldn't post my full comment even after I restarted my phone, anybody know why that might be?
I think both fall into a certain class. Some Ford/Dodge fanbois call the GTO ugly. I genuinely think there isn't anything one could consider offensive about the car. Boring? Mostly. Ugly? Of course not, it's styling is totally cohesive. I think the C55 is the same. There was one near my folks place in South Carolina, so I asked them to stop by, see what they thought(not to buy, it was high mileage, but to see how it held up). My dad said beyond the lip spoiler nothing stuck out to him. It's certainly understated, but no sain person can call a w203 ugly. There are little body mods to do to the GTO though to spice it up, in the right color, it even looks classy. The C, probably just put a blacked out/chrome star grill and be done. Interior, the C has a bit better quality and looks clean, but the GTO has multiple color matched interiors and some of the most comfy seats ever. I personally like loud, in your face cars usually, but these two seem to fit my requirements best.
I can't decide
I like the looks of the G8 over the GTO. But, I'll take the C55 over both. Sounds like you're mind is made up and the GTO is the one! I'd say go for that one 'cause that's the one that does it for you....
That is 1950's logic right there. Displacement is one of maybe 10 things that determine mpg(and OP hasn't clarified what "horrible" is).
Fun is #2 or 3 on my priority list for my next car, mpg... not so much. However, it will be my DD so I still have what I consider an acceptable range and have written a few cars off because of that. My top 2 cars right now are the C55 and 05/06 GTO.
A 5 speed auto, 5.4L C55 is rated 16/22. A 6 speed manual, 6.0L GTO is rated 17/25. This, all the while the GTO weighs over 150lbs more, .3L more displacement, nearly 40 more hp, has a 3.46 rear VS 3.06, a cd of .31 vs .27, and the C55 has twin spark plugs for a more complete burn. The LSx engines are also notorious for beating their ratings when not driven like a mad man.
Why? The main reason is despite the 3.46 VS 3.06 rears, 6th gear in the GTO is .57 VS the C55's .83. It's a huge difference real world, while the C55 is turning 2414rpm's at 70mph the GTO is turning 1826. Have I ruled out the AMG because of that? Certainly not. A test drive back to back when I'm ready to buy will decide that, and my commute to work is
No its called common sense. A 5.4 Litre V8 is gonna get pretty poor MPG whatever decade you are in.
GTO is plain. My cousin owns one, and i used to want it.... but you dont get the same feeling driving an american car as you do with imports. American/non-luxury cars feel cheap. As far as gas mileage, with both cars.... forget about it, you're not gonna see anything close to ratings because the cars are difficult to drive slow.
If fuel efficiency is what you want go lease a Lexus ct200h for $200 a month, you'll save on gas enough to own both cars and pay the lexus payment. lol
I like the looks of the G8 over the GTO. But, I'll take the C55 over both. Sounds like you're mind is made up and the GTO is the one! I'd say go for that one 'cause that's the one that does it for you....
It's always good to see another open mind on a 1 make forum. I'm actually drawn to the AMG more and more and I can't figure out why, considering it's the only automatic car I've even considered. It's just me, the mrs, and our 5yo son, so I want enough space for them, but not cavernous like the G8 or especially Charger. I have a feeling though the 6 speed of the GTO will win me over(along with being able to buy parts with the savings from my change drawer and not a bank loan). It's interior is nice too, if not sparse, as it's an Australian car and not usual 00's GM. I test drove both, but weeks apart.
Originally Posted by Smokey31
No its called common sense. A 5.4 Litre V8 is gonna get pretty poor MPG whatever decade you are in.
Depends on what you call "pretty poor" or 'horrible." The new SLK55 with more of a screamer 5.5 weighs the same as a C55, yet gets 19/28. The 6.2L Vette gets 17/29, and could have technically been even better.
So in the context of OP saying he has a rough idle and gets "horrible" mpg and you respond "It's a V8!" yeah, that sounds stuck in the 50's. 12mpg would mean something is wrong, not that he has a thirsty motor. That's ignoring multiple times a larger motor at lower rpm's has proven capable of getting better mpg then a smaller one at higher rpm's. The 722's 5th is just a ridiculous overdrive.
Last edited by ///AchMeinGott; 07-17-2015 at 03:29 PM.
As low as 15-17mpgs in stop and go traffic and up to 23-25 highway running no A/C. Usually see an average of 18-19mpgs due to daily routes.
Get codes pulled for free first. No codes stored? Then check air filters, plugs and wires and then get crafty because with no codes, it gets tricky quick.
with only 2 full tanks in I'm getting approximately 245-250 miles per tank of fuel with city driving. That averages out to about 15 mpg. I have to admit that I've gotten on the accelerator a few times but mostly it's stop and go traffic with very few highway miles. While I appreciate a good snarky comment, I do realize that I'm not driving my V6 G37. However I did expect to get better mpg than what I'm seeing. I appreciate all the recommendations and my apologies for not giving you all the full story.
So new plugs and air filters is a good place to start? I've also heard that that a bad MAF sensor could be the culprit? Any truth to that?
Well, all info I read says it's a 62L, or 16.3 gallon tank.
If you burn through 15.8 gallons, at 15mpg average, that's 237m/tank
At 17mpg is 268.
At 19mpg is 300.
So at 300 miles most would easily be running on vapors, if not empty. Did you know the comfort(transmisson) mode starts in 2nd gear? If you're in traffic and can't play anyway, leave it in that. Will help keep the rpm's low.
07-15-2015, 03:05 PM
