Mobil 93 Good Shell V Power Not So Good

[dmiller5]

my 08 spec b I can go 70mph and get 29mpg consistantly

[dr_sharp]

You're not getting 26.7 in this kind of driving. Go away.

 

+1

[chenc544]

I'm pretty sure it's a federal mandate that all gas contains 10% ethanol. It has been that way since last summer IIRC.

Anyway, I'm pretty sure you just got your first tank of winter gas. I usually average ~28 mpg on summer gas. I got my first tank of winter gas last week and I got 26.5 mpg on that tank. Either way, you can't make a statement like that base only one tank of gas. Alternating between the 2 for a few tanks each and then you can draw some conclusion from that.

[MAINIAC SPEC B]

I still cannot believe 27 mpg on LGT. Must be 65 mph driving and never in boost.

 

Most of my driving is done on roads with posted speed limits of 35 to 55. I am rarely on I-95 or 16. When I am on the highway for any extended period of time and keep it under 80 I get close to 30 mpg. When I drive the Spec. B. which is not everyday my work horse is my 01 VDC Outback that has 158K 6 cyl. auto I average 24 to 25 mpg. But when I do drive the Spec. B. I do one pull in either 2nd or 3rd to 6000+ just to appreciate this great car. This car has everthing I want. Comfort, great gas mileage, all wheel drive and power when I want it. What`s not to like. When I ran my blueprinted 64 421 HO Bonneville Conv. way back when at National Speedway the best I could do was 13.9 @ 103.5 because I could not get any traction coming off the line running street tires. This was my DD at that time but I only averaged 13 mpg. I was turning around 3600 rpm at 60 with the 4:10 dana rear and no overdrive back then. Also this the Spec. B. is quicker than my 89 Taurus SHO.

[Beanboy]

Octane is only part of the story though. Lots of advantages when is comes to alchohol and FI cars. Much higher evaporative cooling power, more energy released per power cycle, greater exhaust gas volume, lower EGTs.

 

If you drive the same way, a FI car on E85 is going to have less of a mileage hit to boot since you can get more power out of the car versus gasoline. That is if you can keep your foot off the go pedal, hehe.

[Deer Killer]

Octane is only part of the story though. Lots of advantages when is comes to alchohol and FI cars. Much higher evaporative cooling power, more energy released per power cycle, greater exhaust gas volume, lower EGTs.

 

If you drive the same way, a FI car on E85 is going to have less of a mileage hit to boot since you can get more power out of the car versus gasoline. That is if you can keep your foot off the go pedal, hehe.

 

Ethanol: 75,700 BTU/gallon

Gas: 115,000 BTU/gallon

 

1 gallon of ethanol has 65% of the energy as one gallon of gas.

 

You can run more timing with ethanol (Not E10) so you can get more efficiency out of it.. but it's not a miracle.

[MAINIAC SPEC B]

^ I sure am. If I can remember to, I'll take a picture of the OEM info system log for you. You just have to be smart about using the turbo. If there are 5 cars stopped in your lane at the 4-way stop a 1/4 mile away from you, there is no need to go to 4k rpm in second gear just so you can sit behind cars and wear out your clutch waiting for your turn to go. Short shift and "idle" up there timing it out so that you remain in motion as long as possible. Same thing with lights.

 

Your right you have to be intelligent about how you drive to maximize your gas milage so when you do want to have some fun you can still get good overall mileage. My 07 has an MPG gauge that reads + or - and I have educated my right foot to keep it on the + side most of the time even while going up hill. By the way since I live in Maine whats a stop light ? Just kidding.

[msb175]

interesting. i get about 23-25 mpg these days on winter gas. then again, its all highway.

[1-3-2-4]

funny I've always had better gas milage from Shell then Citgo and this was with a NA forester.. I'd get like an extra 15 miles from a tank.

[Jon in CT]

Ethanol: 75,700 BTU/gallon

Gas: 115,000 BTU/gallon

 

1 gallon of ethanol has 65% of the energy as one gallon of gas.

 

You can run more timing with ethanol (Not E10) so you can get more efficiency out of it.. but it's not a miracle.

9.0:1 - Ethanol Stoichiometric A/F Ratio

14.7:1 - Gasoline Stoichiometric A/F Ratio

 

You're ignoring the fact that for each gram of intake air, the gasoline needed to achieve a stoichiometric A/F ratio is only 61% of the ethanol needed. This means that ethanol will release more energy than gasoline given the same amount of intake air, because you need to inject much more of it. And this energy edge is before you jack up the spark advance to take advantage of ethanol's superior knock resistance. It's a miracle.

[Jon in CT]

I'm pretty sure it's a federal mandate that all gas contains 10% ethanol. It has been that way since last summer IIRC.

I'm pretty sure you're wrong. The Energy Policy Act of 2005 removed the oxygenate requirement from the RFG (Re-Formulated Gasoline) program.

[scooby600]

wtf how is my 08 getting 23-24 ish whether I drive in the city or highway? I want good gas mileage

[Zed 2.0]

My 07 has an MPG gauge that reads + or - and I have educated my right foot to keep it on the + side most of the time even while going up hill.

 

The +/- gauge uses your average MPG as its zero point. It's impossible for you to be on the + side most the the time, since this would change your MPG and the +/- gauge would use that higher MPG as your new average.

[Lost Horizon]

so any engine can take 10% ethenol? my dad put in our bimmer the other day and i was wondering what it was all about..

 

Not recommeded for the 335TT direct injection... the High Pressure Fuel Pump to the rail don't like it much, and dies often under that scenario.. although I believe they are coming to grips with the internal materials they now use ..

 

I suspect it may affect other internal seals/poly based stuff in other cars also. It's just not noticeable so soon as it is on the Hi Pressure rail side of the twin Turbo.

 

It appears to be a localized USA problem.

[hamhock]

I came back from the Subaru Challenge which was held in Houston this year. Drove 305 miles on 3/4 of a tank. Averaged 28.8 miles per gallon. Did 65 in Houston, and 75-80 once we got north of it. It's possible to get good gas mileage, just gotta stay outta boost. And this was on a tank of Shell V Power(they didn't have QT in Houston). '08 LGT, with a turboback and UTEC.

 

 

 

 

Mika

[1-3-2-4]

The +/- gauge uses your average MPG as its zero point. It's impossible for you to be on the + side most the the time, since this would change your MPG and the +/- gauge would use that higher MPG as your new average.

 

only way to do it is to lift off the throttle but as you know you slow down.

[MAINIAC SPEC B]

only way to do it is to lift off the throttle but as you know you slow down.

 

The ECO gauge shows the average rate of fuel consumption and this starts from 0 each time you reset the trip meter. It is easy to keep the needle on the + side when statrting from 0. It takes more driving skill to keep it on the + side after 100 miles and even more skill after 200 miles and so on, but it is possible. I`ve done it. Also I do lift off throttle when coming down hills even if the are ever so slight. I have it down to a science going up all the hills I encounter. I know what speed to enter the base and where to lift going up hill so at the crest I am doing posted speed limit and then coming down I am off throttle. I always run in Sport # this is where I get my best gas mileage. I do use I when the roads are snowey or icy.

[1-3-2-4]

Going to be int interesting to see what I get for an Avg. I tend to have a heavy right foot but on long drives I know I got some good millage out of the N/A forester.

 

I might stick with Mobil and Shell for fuel for the first month or so.

[Deer Killer]

;1495991']9.0:1 - Ethanol Stoichiometric A/F Ratio

14.7:1 - Gasoline Stoichiometric A/F Ratio

 

You're ignoring the fact that for each gram of intake air, the gasoline needed to achieve a stoichiometric A/F ratio is only 61% of the ethanol needed. This means that ethanol will release more energy than gasoline given the same amount of intake air, because you need to inject much more of it. And this energy edge is before you jack up the spark advance to take advantage of ethanol's superior knock resistance. It's a miracle.

 

No. I think you're using this 61% number incorrectly.

 

14.7 parts air to 1 part gas: 6.37% fuel charge at a energy mass density of 100%

9 parts air to 1 part ethanol: 10% fuel charge at a energy mass density of 61.51% of gas

 

so total energy of 1 combustion at stoich:

gas: 6.37%

ethanol: 6.151%

[Zed 2.0]

The ECO gauge shows the average rate of fuel consumption and this starts from 0 each time you reset the trip meter. It is easy to keep the needle on the + side when statrting from 0. It takes more driving skill to keep it on the + side after 100 miles and even more skill after 200 miles and so on, but it is possible. I`ve done it. Also I do lift off throttle when coming down hills even if the are ever so slight. I have it down to a science going up all the hills I encounter. I know what speed to enter the base and where to lift going up hill so at the crest I am doing posted speed limit and then coming down I am off throttle. I always run in Sport # this is where I get my best gas mileage. I do use I when the roads are snowey or icy.

 

 

No, the fuel mileage gauge measures your economy over a small distance before displaying anything. It doesn't start from 0. That is why it displays all the way to the - side every time you restart the trip computer. This is all in your manual.

[MAINIAC SPEC B]

No, the fuel mileage gauge measures your economy over a small distance before displaying anything. It doesn't start from 0. That is why it displays all the way to the - side every time you restart the trip computer. This is all in your manual.

 

I have read the manuel from front to back. Once you reset the trip odometer it starts from 0 you just don`t see it. For the 1st mile the average mpg is not shown. After that mine typically says around 20mpg and keeps on improving. I reset my trip odometer prior to leaving the station. The car hasn`t moved yet so it starts at 0 not -1mpg or 1mpg 0. If it started with anything other than 0 the average would be off.

[RudeMood]

I have used only Shell V-Power fuel since I bought my car brand new. I have no problem seeing 380 miles per tank if I drive nicely.

[MAINIAC SPEC B]

I have used only Shell V-Power fuel since I bought my car brand new. I have no problem seeing 380 miles per tank if I drive nicely.

 

How many miles on your car? On one of my rare highway trips I covered 414 miles and when filled up it took 13.9 gal. which equals 29.7 mpg. This left approx. 3 gals left in the tank. I kept it under 80 and had about 5000 miles on the car during that trip and I use Mobil 1 and I ran in Sport # all the way.

[RudeMood]

I believe I am at 7300 miles now

 

I use conventional oil and have no aftermarket mods.

[TambourineMan]

Geez everyone, chill out. You gotta support the pols' friends somehow. Otherwise how do you expect them to get re-elected?