Better gas mileage - Page 3 - PeachParts Mercedes-Benz Forum

Mistress · #31 07-29-2009, 10:08 AM

Quote:

Originally Posted by WVOtoGO

LOL

I know aircraft sure save you money when they're at a dead stop.
But, soon as you yell "CLEAR!!", there's this great big sucking sound.

music to my ears...

WVOtoGO · #32 07-29-2009, 10:14 AM

Quote:

Originally Posted by Mistress

music to my ears...

Mine too.

That is...right up until I see that tanker truck pulling up the drive every month.

MS Fowler · #33 07-29-2009, 10:16 AM

Quote:

Originally Posted by 037981

1 drive nice and slow

8 get the best gas/petrol you can get premium/high octane

Good list but I disagree with this one. High octane gas has LESS energy than regular. High test is made to burn slower, thus is less prone to knocking. If you car runs on regular, you will gain NO benefit from using high octance gas.

On some engines, the engine control management system may use different ignition advance curves based on the octane of the fuel. Those engine will experience more economy (mpg) with the better gas. However, the cost/mile may still be lower with regular fuel, UNLESS your owner's manual specificallt requires premium fuel.

tbomachines · #34 07-29-2009, 10:19 AM

Quote:

Originally Posted by 037981

yes it will have a affect but not as much as naturally aspirated
on you have to got 2 Hiclone 1 in front of the turbo and 1 after
my brother has two Hiclone in his turbodiesel and he gets better fuel mileage

So he has one in between the turbo and the intake manifold??? If the one before wasn't pointless, that one is. The turbo is going to spin the air anyways, first of all. Next, circulating the air going into the intake manifold seems rather pointless because (as WVO said) it will then be distributed to however many cylinders there are. Unless your brother has a custom intake manifold I'm afraid hes wasted his money.

MS Fowler · #35 07-29-2009, 10:21 AM

Quote:

Originally Posted by tbomachines

So he has one in between the turbo and the intake manifold??? If the one before wasn't pointless, that one is. The turbo is going to spin the air anyways, first of all. Next, circulating the air going into the intake manifold seems rather pointless because (as WVO said) it will then be distributed to however many cylinders there are. Unless your brother has a custom intake manifold I'm afraid hes wasted his money.

He has also placed an obstruction in the intake. Can't help.

WVOtoGO · #36 07-29-2009, 10:26 AM

Quote:

Originally Posted by MS Fowler

Good list but I disagree with this one. High octane gas has LESS energy than regular. High test is made to burn slower, thus is less prone to knocking. If you car runs on regular, you will gain NO benefit from using high octance gas.

On some engines, the engine control management system may use different ignition advance curves based on the octane of the fuel. Those engine will experience more economy (mpg) with the better gas. However, the cost/mile may still be lower with regular fuel, UNLESS your owner's manual specificallt requires premium fuel.

That’s exactly what I though when reading it.

I knew we had this subject come up just a week or so ago here.

Thanks for touching on this important fact again.

Many folks seem to think that more of anything is better.
Not always so with regard to octane ratings and what’s best for your car and its performance.

WVOtoGO · #37 07-29-2009, 10:29 AM

Quote:

Originally Posted by MS Fowler

He has also placed an obstruction in the intake. Can't help.

BINGO !!

X2

X3, if you count what Shelby said in post 23.

TheDon · #38 07-29-2009, 10:34 AM

Quote:

Originally Posted by BobK

depends on a bunch of factors. What car, what road, what wind direction and speed, how much stop and go, what tire inflation? During the 55 years, it was figured they could have saved more gas if they had keep the speed limit at 70 and mandated 4 more psi in all tires. My SDL got better mpg at 75-80. Found that out when I was making almost daily 200 mile round trips when mom was sick. Went from 23 to 27 mpg. My old '74 Datsun 260Z barely got 20mpg at 55, but got 26.5 at 85mph. Whole lotta factors involved...but that doesn't fit in the safety nazi or car haters agenda.

I dont know, I got 32 mpg in the SDL by doing a steady 60 mph for an entire trip.

your mpg's will drop severely at anything above 65-70 since the power needed to travel at those speeds doubles due to the wind resistance.

tyl604 · #39 07-29-2009, 12:00 PM

The owner's manual for my Lexus says use premium gasoline. Then it says regular is OK but the gas mileage will suffer some. My reading of this is that the computer adjusts the engine to regular and therefore it is OK to run regular in it; perhaps extrapolate this concept to all other cars too.

MS Fowler · #40 07-29-2009, 12:12 PM

Quote:

Originally Posted by tyl604

The owner's manual for my Lexus says use premium gasoline. Then it says regular is OK but the gas mileage will suffer some. My reading of this is that the computer adjusts the engine to regular and therefore it is OK to run regular in it; perhaps extrapolate this concept to all other cars too.

Don't extrapolate. Different manufacturers use different technology and computer programs. Some will advance the normal timing if high octance is used. Others will only retard if the octane is low, but can't give an increase for the hi-test.
Since your Lexus says you can use either, you should run a few tankfuls of hi-test, and then a few of regular, keeping careful records, and see which is more economical for your car and your driving. Improved gas mileage alone does not mean hi-test is cheaper--paying 3% more for hi-test only to get a 2% improvement would not make economic sense. However if paying 3% more gets a 5% inmprovement, then you are saving money by buying the better gas.
Also factor in how you drive--If your car accelearates faster on hi-test, and that is important to you, then the cost may not matter.

And remember, " Your mileage may vary".

EricSilver · #41 07-29-2009, 12:51 PM

My best fuel economy occurs at 75-80mph. I am convinced the 55mph propaganda was originated by the oil industry.

MS Fowler · #42 07-29-2009, 01:04 PM

You better not sell that car. Your experience runs counter to just about everyone else's.

I'm not calling BS, but it is strange.

EricSilver · #43 07-29-2009, 01:29 PM

Quote:

Originally Posted by MS Fowler

You better not sell that car. Your experience runs counter to just about everyone else's.

I'm not calling BS, but it is strange.

I never thought it was unusual -- until now.

At 65-70 mph (on the Wash. DC beltway) I get 100-105 miles from full tank to the 3/4 full mark.

At 75-80 mph (on I-95) I get 120-125 miles from full tank to the 3/4 full mark. This one I know as fact because my sister lives exactly 126 miles from me and I can drive door-to-door from VA to DE on 1/4 tank. (I have made this trip dozens of times with the same results.)

Both examples include time on local roads between highways.

I conjecture that at higher speeds more oxygen is being rammed into the intake and the car adjusts to leaner running.

MS Fowler · #44 07-29-2009, 01:35 PM

Quote:

Originally Posted by EricSilver

I never thought it was unusual -- until now.

At 65-70 mph (on the Wash. DC beltway) I get 100-105 miles from full tank to the 3/4 full mark.

At 75-80 mph (on I-95) I get 120-125 miles from full tank to the 3/4 full mark. This one I know as fact because my sister lives exactly 126 miles from me and I can drive door-to-door from VA to DE on 1/4 tank. (I have made this trip dozens of times with the same results.)

Both examples include time on local roads between highways.

I conjecture that at higher speeds more oxygen is being rammed into the intake and the car adjusts to leaner running.

The only reliable way to compute mileage is from full tank to full tank and average over several tanks. Using the gas gauge invites error.

EricSilver · #45 07-29-2009, 01:43 PM

Quote:

Originally Posted by MS Fowler

The only reliable way to compute mileage is from full tank to full tank and average over several tanks. Using the gas gauge invites error.

I do, and the patterns are always the same -- F to 3/4, 3/4 to 1/2, and 1/2 to 1/4 show the same mileage, with a significant drop-off from 1/4 to E. (I rarely run it below 1/4.)

Obviously, the gauge is not calibrated to measure fuel capacity evenly. When I top off from 3/4 to full, or from 1/2 to 3/4, 4 gallons does it each time. But only about 3 gal is needed to go from near E to 1/4 )or slightly above).