How heavy is your foot?
02-27-2010, 09:07 PM
#26
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a quarter mile at a time
The whole problem with gasoline spark ignited Otto cycle engines is that they suffer pumping losses at partial load/throttle. That is why Benz developed the Diesotto.
This is why a low capacity 4 will give good economy in town piddling around where a larger six will loose out. However - load the car & go on a high speed cruise & the six will win every time. Taking this argument to the extreme with a modern, efficient engine that breathes well & the ideal is to try & run a larger engine as close to stoichiometric AF ratio or leaner at constant RPM via a CVT. The 7G tries to do this. An engine like the 272 - 350 will give huge economy leaned out & running at a constant 2800 to 3000RPM - You can't really do this with the 271 without flat spots & driveability problems. It needs more fuel to achieve smooth running & high output.
This is well illustrated in the new Prius where Toyota have taken the engine size to 1800cc from 1500 to achieve better performance without giving up economy & emissions.
The Prius is, however, a dumb vehicle with all it's complexity. Diesel engines don't suffer these pumping losses at part fuel input & a little diesel Citroen will run rings around a Prius from a performance perspective while achieving 70 mpg. I'd rather have the Citroen thanks & I don't particularly like French cars.
This is also why I object to legislators trying to impose engine capacity restrictions on OEMS - rather tell them max emissions per mile or whatever will be tolerated & let the developers achieve it as they wish. I'll bet they will do this for the average family saloon with a six cylinder, approx square, petrol engine with one small turbo of 2 to 3 litres running at close to constant RPM via a CVT or 7 or 8 speed auto.
If the turbo Diesotto can be built economically then you can have the best of both worlds & possibly reduce capacity a little over a pure spark ignited engine. Further development of Atkinson cycle engines is also possible but this would require OEMs to raise capacity to achieve a specific output.
This is why a low capacity 4 will give good economy in town piddling around where a larger six will loose out. However - load the car & go on a high speed cruise & the six will win every time. Taking this argument to the extreme with a modern, efficient engine that breathes well & the ideal is to try & run a larger engine as close to stoichiometric AF ratio or leaner at constant RPM via a CVT. The 7G tries to do this. An engine like the 272 - 350 will give huge economy leaned out & running at a constant 2800 to 3000RPM - You can't really do this with the 271 without flat spots & driveability problems. It needs more fuel to achieve smooth running & high output.
This is well illustrated in the new Prius where Toyota have taken the engine size to 1800cc from 1500 to achieve better performance without giving up economy & emissions.
The Prius is, however, a dumb vehicle with all it's complexity. Diesel engines don't suffer these pumping losses at part fuel input & a little diesel Citroen will run rings around a Prius from a performance perspective while achieving 70 mpg. I'd rather have the Citroen thanks & I don't particularly like French cars.
This is also why I object to legislators trying to impose engine capacity restrictions on OEMS - rather tell them max emissions per mile or whatever will be tolerated & let the developers achieve it as they wish. I'll bet they will do this for the average family saloon with a six cylinder, approx square, petrol engine with one small turbo of 2 to 3 litres running at close to constant RPM via a CVT or 7 or 8 speed auto.
If the turbo Diesotto can be built economically then you can have the best of both worlds & possibly reduce capacity a little over a pure spark ignited engine. Further development of Atkinson cycle engines is also possible but this would require OEMs to raise capacity to achieve a specific output.
02-27-2010, 10:15 PM
#27
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02-27-2010, 10:17 PM
#28
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Eric, that's pretty much my experience with the C350 I had for a week (W204). It got much better fuel economy than the 07 C230 that a relative purchased and I've driven a few times. The 7G also seemed to work much better in that application.
02-27-2010, 10:27 PM
#31
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1999 CLK320 (sold), 2007 C230 SS (gone), 2000 Grand Marquis, 2011 CR-Z, stay tuned...
My average since the last reset (last service - 10,000+) is 24.6. I have gotten 24.6 or 24.7 since I have owned the car.
02-27-2010, 10:37 PM
#32
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The M271 is capable of very, very good mileage on the freeway. I got 31mpg on a trip where I ran exclusively interstate, 200 miles, at 80-90mph the whole way. On a 150 mile journey with 5 adults on the car at similar speeds, I got 26.5. .
After a trip to Tampa, FL to a funeral. The car was very, very loaded (5 adults, two larger men, 1 pregnant woman plus light luggage) and there were hundreds of those miles traveled at 85mph or better. This includes time that the car spent idling in 97F weather, AC full blast, during the funeral services - it idled probably a total of 45 minutes getting 0mpg.
This was leg 1 of that funeral journey.. 1st tank. It could be better, but we took GA-41S that night (instead of 75S) which has some hills and numerous red lights.
This was when we arrived in Tampa. The last 226 miles of our journey, including a stop at a rest area to change clothes and freshen up. Knowing that we stopped and the car idled averaging both 0mpg and 0mph, do you realize how fast we must've been going to have averaged 77mph over 226 miles? Trust me.. we were running late and hauling ***. I think my car did very well on fuel given this situation.. the heat, the huge load, the demanding speeds.
After a trip to Tampa, FL to a funeral. The car was very, very loaded (5 adults, two larger men, 1 pregnant woman plus light luggage) and there were hundreds of those miles traveled at 85mph or better. This includes time that the car spent idling in 97F weather, AC full blast, during the funeral services - it idled probably a total of 45 minutes getting 0mpg.
This was leg 1 of that funeral journey.. 1st tank. It could be better, but we took GA-41S that night (instead of 75S) which has some hills and numerous red lights.
This was when we arrived in Tampa. The last 226 miles of our journey, including a stop at a rest area to change clothes and freshen up. Knowing that we stopped and the car idled averaging both 0mpg and 0mph, do you realize how fast we must've been going to have averaged 77mph over 226 miles? Trust me.. we were running late and hauling ***. I think my car did very well on fuel given this situation.. the heat, the huge load, the demanding speeds.
Last edited by LILBENZ230; 02-27-2010 at 10:43 PM.
02-28-2010, 12:36 AM
#33
Super Moderator
I hate you guys. :)
Bloody C32 recently registered a cumulative ~5000 mile MFD average of 13.6 mpg.
No picture to share owing to its battery disconnect during February service.
The Mrs.’ two mile (each direction) daily commute conspires against any reasonable consumption figures. Don’t believe she’s ever been past half throttle, ‘cept as a passenger haha. That, twisting an appropriately overdriven Lysholm, a relatively low compression ratio and detonation-quenching AFR/conservative spark timing ensure it’ll never be particularly thrifty. Initial purchaser paid a hefty EPA ‘gas guzzler’ tariff upon delivery and, in reality, during each subsequent filling station visit. Chugs down dinosaur derivatives at the rate of about 8 mpg during spirited closed course events. It’ll go about 22 miles at a steady - straight and level - 75 mph while consuming a gallon of California’s reformulated blend – with a tailwind. Upside is that during its stringent biannual tailpipe sniffer testing it blows almost as clean as a spring breeze.
Carbon footprint be damned. We’re environmentally conscious in other ways.
Not quite ready to ditch its intoxicating thrust for a sensible machine.
Bloody C32 recently registered a cumulative ~5000 mile MFD average of 13.6 mpg.
No picture to share owing to its battery disconnect during February service.
The Mrs.’ two mile (each direction) daily commute conspires against any reasonable consumption figures. Don’t believe she’s ever been past half throttle, ‘cept as a passenger haha. That, twisting an appropriately overdriven Lysholm, a relatively low compression ratio and detonation-quenching AFR/conservative spark timing ensure it’ll never be particularly thrifty. Initial purchaser paid a hefty EPA ‘gas guzzler’ tariff upon delivery and, in reality, during each subsequent filling station visit. Chugs down dinosaur derivatives at the rate of about 8 mpg during spirited closed course events. It’ll go about 22 miles at a steady - straight and level - 75 mph while consuming a gallon of California’s reformulated blend – with a tailwind. Upside is that during its stringent biannual tailpipe sniffer testing it blows almost as clean as a spring breeze.
Carbon footprint be damned. We’re environmentally conscious in other ways.
Not quite ready to ditch its intoxicating thrust for a sensible machine.
02-28-2010, 02:33 AM
#35
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02-28-2010, 02:36 AM
#36
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07 E63. 07 STi limited #606/800
what is this some kinda amputee joke? my prosthetic weighs 1.2 lbs.
lol jk, sorry i had to post this, i joke around about my combat loss.
lol jk, sorry i had to post this, i joke around about my combat loss.
02-28-2010, 02:38 AM
#37
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(no offense to people who had their body part/parts amputated)
02-28-2010, 02:47 AM
#38
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07 E63. 07 STi limited #606/800
haha well im one of those who had my leg blown off. only 700 of us that lost in combat i think most amputations occur cause of accidents or health problems.
i think some people forget about the war. someone asked me how i lost my leg, when it clearly has a US Flag on the front and a US ARMY nametape and a sticker that says IRAQ I SERVED on the back . i told him "iraq"
and he replies, o a wreck huh?
i say "NO! IRAQ! you know that war thats going on over there that a lot of people seem to forget!"
i think some people forget about the war. someone asked me how i lost my leg, when it clearly has a US Flag on the front and a US ARMY nametape and a sticker that says IRAQ I SERVED on the back . i told him "iraq"
and he replies, o a wreck huh?
i say "NO! IRAQ! you know that war thats going on over there that a lot of people seem to forget!"
02-28-2010, 03:38 AM
#39
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2005 C320 Sport, 2010 C300 Sport
Infantry.. Since you mentioned your leg, I couldn't help but think of my friend Ramin. Check this out. I took this photo while @ SEMA this past year.
Yup! that bad boy is signed by Ken Block too! lol
Yup! that bad boy is signed by Ken Block too! lol
02-28-2010, 04:06 AM
#40
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03 g35 coupe...........02 c32 Sold
Are you driving mostly city or highway? I think you only need to be worried if your getting crap numbers doing highway driving. Your mpg numbers will always be low if your doing mostly city driving. Whats your MPG when your at stop light? Right?
Try accelerating slower, cruise at a constant rpm on the highway, keep your highway speed to 65mph and up your tire psi to 40 and it should improve your mileage.
My stock c32 got 27mpg before. Now i'm Dynoing close to 360whp with a rich LET tune and i still average 22mpg.
Try accelerating slower, cruise at a constant rpm on the highway, keep your highway speed to 65mph and up your tire psi to 40 and it should improve your mileage.
My stock c32 got 27mpg before. Now i'm Dynoing close to 360whp with a rich LET tune and i still average 22mpg.
02-28-2010, 04:15 AM
#41
Super Moderator
Yes, LILBENZ230, indeed it is.
Cold starts, without an ensuing proper warm-up drive cycle of sufficient duration, are hell on any engine’s ultimate longevity.
Excluding other consumables and its requisite operating expenses, a gallon of petrol each week for getting to and fro one’s place of gainful employment is envied by most other Southern California residents. Only telecommuting would likely require less. Rather hard to accomplish when you’re a tenured MS whose calling is to be in front of her students. Nonetheless, our C has proven to be relatively cheap and safe transportation.
Trust you know it’s my place to ensure its crankcase contaminants are boiled off with appropriate regularity.
Cold starts, without an ensuing proper warm-up drive cycle of sufficient duration, are hell on any engine’s ultimate longevity.
Excluding other consumables and its requisite operating expenses, a gallon of petrol each week for getting to and fro one’s place of gainful employment is envied by most other Southern California residents. Only telecommuting would likely require less. Rather hard to accomplish when you’re a tenured MS whose calling is to be in front of her students. Nonetheless, our C has proven to be relatively cheap and safe transportation.
Trust you know it’s my place to ensure its crankcase contaminants are boiled off with appropriate regularity.
02-28-2010, 05:33 AM
#44
Super Moderator
Yes - my poor car runs a similar duty cycle - not quite as harsh - and running open loop in the warm up phases is not a fair reflection of consumption. For this reason I don't mind MBSA's 15,000Km drain intervals. A spirited run to blow out the cobwebs to a dinner at my sister's last night over 2 mountain passes achieved 8.9l/100 over a round trip of 74Km with two warm up cycles & frequent red lining, which is 31.7 mpg (real imperial gallons) or 26.43 US mpg. Open road high speed cruising with no attempts to save fuel takes her well into the > 30 US mpg range all of which I consider most satisfactory for the pleasures of driving a smooth six. You must remember that I do most of my running at coast & the 2.6 is fine. At high altitude such as Johannesburg I'll have the W204 350 7G any time thanks even though one sacrifices a little of the smoothness. The small valve sizes in the 2.6 show their limitations at high altitude. This is where forced induction helps to altitude compensate.
But indeed splinter - our 3 valve per cylinder engines achieve true LEV status & blow some of the cleanest tailpies around - albeit yours with a lot more excitement one can unleash with a prod of the loud pedal. From a green perspective I'm not unhappy with my overall carbon footprint.
But indeed splinter - our 3 valve per cylinder engines achieve true LEV status & blow some of the cleanest tailpies around - albeit yours with a lot more excitement one can unleash with a prod of the loud pedal. From a green perspective I'm not unhappy with my overall carbon footprint.
02-28-2010, 01:28 PM
#45
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03-08-2010, 11:49 AM
#49
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2007 C230 and 1985 Monte SS
You're doing something wrong, or there is something wrong with the car. My LIFETIME average with premium is 25MPG. On a recent trip from CA, I got a personal best of 29.4MPG driving 75-85MPH on the highway (In OR which is FAR from flat).
Karo, that is some ugly mileage, LOL.
Karo, that is some ugly mileage, LOL.
2.5L M272, 7G
03-15-2010, 02:38 PM
#50
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2005 C320 Sport, 2010 C300 Sport
Wow you guys are amazing. I just did a Vegas trip this past weekend and was able to average at best 27.6 mpg after driving 320miles.
