Mileage using Shell suddenly goes down

JackDodge · 12-13-2006, 04:34 PM

I've been using Shell for quite a while; since the beginning of summer or earlier. I've generally used the same gas station too. However, three tanks ago, my mileage dropped further than it ever has before. Even during very cold winter months, I've been able to get at least 50 mpg. However, the last two tanks at Shell got an average of only 48 if I was lucky and was really around 46 most of the time. That's awful for me. At first, I wrote it off to too much acceleration or what ever but the route away from the gas station is 25 mph for several miles and then 35 after that so I'm usually able to get the car in to electric mode in the 25 mph part of the trip. By the time I'm in the office, usually, I have an average mpg of 58 to 60 although it never lasts but settles down to around 55 or 56. Both Shell tanks, I couldn't get the car to go in to electric mode much at all in the 25 mph part of the trip. I checked the tire pressure but couldn't think of anything out of the ordinary; we're not exactly in a snow belt here.

This morning, I decided to stop at a Mobil station that is several miles earlier in my trip or just a couple of miles from my house. By the time I got to the aforementioned 35 mph of my route, my average mpg was back where it usually is. The car didn't complain or exhibit any behavior other than the lower average mileage with the Shell gas but I'm wondering if anyone else has noticed this kind of mileage drop from Shell or possibly that the station I go to has been getting gasoline that's below average for them.

F8L · 12-13-2006, 05:07 PM

I think I predominately use Shell because its colse to my house. My milage went to hell and a handbasket a few months ago but I attribute that to added weight in the car and the cold temps. Right now I'm gettign 41mpg avg. with easy driving. No hypermiling though.

JimN · 12-13-2006, 09:50 PM

Perhaps the Shell stations started selling an alcohol blend. In NJ the alcohol percentage is not specifically disclosed. The label on the pump states "may contain up to 10%..." So, is the "gasoline" being pumped really 100% gasoline?

F8L · 12-13-2006, 09:59 PM

<div class='quotetop'>QUOTE(JimN @ Dec 13 2006, 06:50 PM) [snapback]361982[/snapback]</div>

Quote:

Perhaps the Shell stations started selling an alcohol blend. In NJ the alcohol percentage is not specifically disclosed. The label on the pump states "may contain up to 10%..." So, is the "gasoline" being pumped really 100% gasoline?
[/b]

Well in your case the mafia may be putting toxic waste into the gasoline again. Not like they havn't done it before. Ha!

NicNicholson · 12-14-2006, 07:18 PM

I would love to hear what happens if you go back and forth a couple of times... Shell--mileage drop, Mobil--mileage increase, etc...

Keep us informed if you decide to try that.

donee · 12-14-2006, 08:50 PM

Hi Jack,

I have just had something similar to the opposite happen. Been driving on BP mostly. Then the day before the cold weather I filled up on the way to work with Mobil at a station along the way (other stations were all busy), rather than be caught in the cold weather without gas. Car was running rough from that time. Engine would buck a little on idle. Almost like one cylinder was having trouble firing. Got 41 mpg on the tank through the week-and-a-half of cold weather, even using the block heater. Refilled with Shell this weekend, and voila, car purs, and up to 53 mpg, without using the block heater.

Think its just the combination of cold weather and a Mobil station with some water in their tanks.

JackDodge · 12-15-2006, 04:02 PM

<div class='quotetop'>QUOTE(donee @ Dec 14 2006, 08:50 PM) [snapback]362546[/snapback]</div>

Quote:

Hi Jack,

I have just had something similar to the opposite happen. Been driving on BP mostly. Then the day before the cold weather I filled up on the way to work with Mobil at a station along the way (other stations were all busy), rather than be caught in the cold weather without gas. Car was running rough from that time. Engine would buck a little on idle. Almost like one cylinder was having trouble firing. Got 41 mpg on the tank through the week-and-a-half of cold weather, even using the block heater. Refilled with Shell this weekend, and voila, car purs, and up to 53 mpg, without using the block heater.

Think its just the combination of cold weather and a Mobil station with some water in their tanks.
[/b]

I don't know, it seems that if there was water in the tank, it would affect performance in a more obvious way but maybe the gasoline they'd been getting wasn't quite as good as it should be. You can't fool a Prius owner because of the way we watch our mileage. Shell around here is usually more expensive by around five cents than the rest; I didn't mind paying more as long as the mileage was good but I'll stick with Mobil until mileage sucks from that one as well

12-13-2006, 04:34 PM	#1
JackDodge Gold Member Join Date: Sep 2005 Location: Bloomfield Hills, MI Posts: 2,375 My Car: Other Hybrid Model: Package: N/A Thanks: 2 Thanked 2 Times in 2 Posts Friends: 0	I've been using Shell for quite a while; since the beginning of summer or earlier. I've generally used the same gas station too. However, three tanks ago, my mileage dropped further than it ever has before. Even during very cold winter months, I've been able to get at least 50 mpg. However, the last two tanks at Shell got an average of only 48 if I was lucky and was really around 46 most of the time. That's awful for me. At first, I wrote it off to too much acceleration or what ever but the route away from the gas station is 25 mph for several miles and then 35 after that so I'm usually able to get the car in to electric mode in the 25 mph part of the trip. By the time I'm in the office, usually, I have an average mpg of 58 to 60 although it never lasts but settles down to around 55 or 56. Both Shell tanks, I couldn't get the car to go in to electric mode much at all in the 25 mph part of the trip. I checked the tire pressure but couldn't think of anything out of the ordinary; we're not exactly in a snow belt here. This morning, I decided to stop at a Mobil station that is several miles earlier in my trip or just a couple of miles from my house. By the time I got to the aforementioned 35 mph of my route, my average mpg was back where it usually is. The car didn't complain or exhibit any behavior other than the lower average mileage with the Shell gas but I'm wondering if anyone else has noticed this kind of mileage drop from Shell or possibly that the station I go to has been getting gasoline that's below average for them. __________________ "Isolation exists only in isolation. Once shared, it evaporates" - Dr. Breuer from the movie "When Nietzsche Wept"

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12-13-2006, 05:07 PM	#2
F8L Collecting Data on Nature Join Date: Aug 2006 Location: Sacramento, CA. Posts: 5,518 My Car: 2005 Prius Model: Package: #4 Thanks: 22 Thanked 190 Times in 138 Posts Friends: 35	I think I predominately use Shell because its colse to my house. My milage went to hell and a handbasket a few months ago but I attribute that to added weight in the car and the cold temps. Right now I'm gettign 41mpg avg. with easy driving. No hypermiling though.

12-13-2006, 09:50 PM	#3
JimN P719 of ??? Join Date: Nov 2006 Location: South Jersey Posts: 2,702 My Car: 2006 Prius Model: N/A Package: #3 Thanks: 0 Thanked 30 Times in 28 Posts Friends: 2	Perhaps the Shell stations started selling an alcohol blend. In NJ the alcohol percentage is not specifically disclosed. The label on the pump states "may contain up to 10%..." So, is the "gasoline" being pumped really 100% gasoline?

12-14-2006, 07:18 PM	#5
NicNicholson Join Date: Sep 2006 Posts: 4 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	I would love to hear what happens if you go back and forth a couple of times... Shell--mileage drop, Mobil--mileage increase, etc... Keep us informed if you decide to try that.

12-14-2006, 08:50 PM	#6
donee Senior Member Join Date: Aug 2005 Location: Chicagoland Posts: 2,244 My Car: 2006 Prius Model: Package: #2 Thanks: 2 Thanked 54 Times in 47 Posts Friends: 0	Hi Jack, I have just had something similar to the opposite happen. Been driving on BP mostly. Then the day before the cold weather I filled up on the way to work with Mobil at a station along the way (other stations were all busy), rather than be caught in the cold weather without gas. Car was running rough from that time. Engine would buck a little on idle. Almost like one cylinder was having trouble firing. Got 41 mpg on the tank through the week-and-a-half of cold weather, even using the block heater. Refilled with Shell this weekend, and voila, car purs, and up to 53 mpg, without using the block heater. Think its just the combination of cold weather and a Mobil station with some water in their tanks.