Reply
 
Thread Tools Search this Thread Display Modes
 
Old 06-06-2006, 11:04 AM   #1
Naysayer
 
Boondocker's Avatar

 
1968 24' Tradewind
Louisville , earth
Join Date: Jun 2005
Posts: 4,635
Images: 7
Send a message via Yahoo to Boondocker
Is there an advantage?

Is there a mileage advantage to be had from using premium fuel? I have always wondered and a new thread by Toastys dad got me thinking.....
__________________

__________________
Rodney

Visit my photography page
and the
Favorite camp grounds project map
My Blog

(The artist formerly known as General Disarray)

Boondocker is offline   Reply With Quote
Old 06-06-2006, 12:22 PM   #2
Rivet Master
 
87MH's Avatar
 
1978 31' Sovereign
Texas Airstream Harbor , Zavalla, in the Deep East Texas Piney Woods on Lake Sam Rayburn
Join Date: Jan 2003
Posts: 2,435
Images: 292
Quote:
Originally Posted by Gen Disarray
Is there a mileage advantage to be had from using premium fuel? .....
Only if your engine is set up with a computer to advance the timing to an optimal ignition advance point just before "pinging" occurs - the "premium" gas is sold with a higher octane (ping retardant) rating.

If no such automatic timing device there will be absolutely no difference in gas mileage between an 87 octane gas and a 140 octane Aviation Fuel.

Note that without a computer constantly monitoring the engine it is very dangerous to advance the timing too much beyond manufacturers suggestions....an internal detonation (ping) could lead very quickly to a "kiss of death" for your motor.

So, a quick answer to your question - IF your engine is set up to take advantage of an increase in power due to an internally regulated advance mechanism and IF the compression ratio remains constant - then yes, the mpg could be marginally improved, to the extent that a more aggresive timing advance would benefit.

Both Premium and Regular (High and Low Octane Rating) gas contain the same BTU's per gallon. One of the reasons that gas is less efficient when compared to a Diesel Fueled engine is that there are more BTU's per gallon of Diesel compared to a gallon of gasoline (it weighs more, therefore there is more hydrocarbon to combust in a gallon of Diesel). One other reason of increased mileage (efficiency) of the Diesel is the incredibly high compression ratio present when the diesel/air mixture starts to burn.
__________________

__________________
Dennis

"Suck it up, spend the bucks, do it right the first time."

WBCCI # 1113
AirForums #1737

Trailer '78 31' Sovereign

Living Large at an Airstream Park on the Largest Lake Totally Contained in Texas
Texas Airstream Harbor, Inc.
87MH is offline   Reply With Quote
Old 06-06-2006, 12:28 PM   #3
Naysayer
 
Boondocker's Avatar

 
1968 24' Tradewind
Louisville , earth
Join Date: Jun 2005
Posts: 4,635
Images: 7
Send a message via Yahoo to Boondocker
Quote:
Originally Posted by 87MH
So, a quick answer to your question - IF your engine is set up to take advantage of an increase in power due to an internally regulated advance mechanism - then yes, the mpg could be marginally improved
My engine is a 1991 ford 302. So do I get this right, using premuim gas can be bad for the engine???
__________________
Rodney

Visit my photography page
and the
Favorite camp grounds project map
My Blog

(The artist formerly known as General Disarray)

Boondocker is offline   Reply With Quote
Old 06-06-2006, 12:41 PM   #4
Rivet Master
 
87MH's Avatar
 
1978 31' Sovereign
Texas Airstream Harbor , Zavalla, in the Deep East Texas Piney Woods on Lake Sam Rayburn
Join Date: Jan 2003
Posts: 2,435
Images: 292
Quote:
Originally Posted by Gen Disarray
My engine is a 1991 ford 302. So do I get this right, using premuim gas can be bad for the engine???
No, I did not mean to infer that at all, I simply stated that, given the engine will not advance the timing to the "ping point", the mpg will not change simply because you run "Premium" vs. "Regular" through the combustion chambers.

Quite the contrary (to being bad for the engine), there may well be additional "cleaner" additives in the premium gas as compared to the regular. Unfortunately, until the retailer gives a thorough listing of all of the additives in each of his grade of gasolines (and that will NEVER happen) you will never know for sure if his claims (if any) to a "cleaner engine" are true or if he is just selling you a crock of crap for a hefty adder on each gallon of gasoline.

Rest assured, you will not damage your engine by running a higher grade of gas than what the manufacturer calls for - you will just, in my opinion, be paying a bunch more for a gallon of gas than what you need to.

One important caveat - IF your engine calls for a certain grade of octane rating, you are certainly taking a chance of damaging your engine should you decide to purchase a gasoline with an octane rating BELOW the manufacturers spec.
__________________
Dennis

"Suck it up, spend the bucks, do it right the first time."

WBCCI # 1113
AirForums #1737

Trailer '78 31' Sovereign

Living Large at an Airstream Park on the Largest Lake Totally Contained in Texas
Texas Airstream Harbor, Inc.
87MH is offline   Reply With Quote
Old 06-06-2006, 01:03 PM   #5
3 Rivet Member
 
Toasty's Dad's Avatar
 
2004 16' International CCD
Cincinnati , Ohio
Join Date: Nov 2005
Posts: 119
hi,

so as the guy who reported the mileage increase, i'm not quite sure what to make of all this. we seem to have done about 2 mpg better while running on premium.

our mileage varied a fair amount from tank to tank, but the 2 mpg was averaged over the roughly 6 tanks it took us to get out west (regular), and the 6 it took to get back (premium), with a total distance of about 1200 miles each way. if anything, we used the AC a bit more on the way back, as temps were 100 in TX/OK.

so from what you say, i either must have this advance feature in my engine's control system, or the "improvement" was due to some other factor. i'll grant that chance may be responsible, since i can't guarantee that we drove EXACTLY the same in each direction.

or perhaps a change in engine operation? we _did_ have an oil change in NM, right before our first tank of premium.

cornfused,
jon
__________________
Toasty's Dad is offline   Reply With Quote
Old 06-06-2006, 01:05 PM   #6
Naysayer
 
Boondocker's Avatar

 
1968 24' Tradewind
Louisville , earth
Join Date: Jun 2005
Posts: 4,635
Images: 7
Send a message via Yahoo to Boondocker
I wonder if wind was a factor....
__________________
Rodney

Visit my photography page
and the
Favorite camp grounds project map
My Blog

(The artist formerly known as General Disarray)

Boondocker is offline   Reply With Quote
Old 06-06-2006, 01:11 PM   #7
Rivet Master
 
myoung's Avatar
 
Nipomo , California
Join Date: Sep 2005
Posts: 627
Images: 24
Hummm. Ohio to New Mexico is uphill. New Mexico to Ohio is downhill. It's easier to walk downhill than uphill.
__________________
Mike Young & Rosemary Nelson

Bowlus Road Chief "Endymion" (coming soon)
BMW X3 xDrive 28D
myoung is offline   Reply With Quote
Old 06-06-2006, 01:43 PM   #8
Rivet Master
 
87MH's Avatar
 
1978 31' Sovereign
Texas Airstream Harbor , Zavalla, in the Deep East Texas Piney Woods on Lake Sam Rayburn
Join Date: Jan 2003
Posts: 2,435
Images: 292
Quote:
Originally Posted by Toasty's Dad
...so as the guy who reported the mileage increase, i'm not quite sure what to make of all this. we seem to have done about 2 mpg better while running on premium. ....so from what you say, i either must have this advance feature in my engine's control system, or the "improvement" was due to some other factor. i'll grant that chance may be responsible, since i can't guarantee that we drove EXACTLY the same in each direction....
I pulled this quote from the Honda Ridgeline website -


The i-VTEC® engine enhances the effect of VTEC® on the V-6 engine by adding variable timing control, or VTC. VTC is a hydraulically operated system that controls the timing of the chain-driven intake camshaft, advancing or retarding it during the intake cycle.


I would have to assume that if they are advancing and retarding the cam, the ignition timing is also changing.

I would further say that your engine was operating efficiently and therefore was able to produce an extra +/- 20% mileage increase for about a 10% price differential in premium vs regular gas.

The BIG question is whether or not it will be able to do the same thing 150,000 miles down the road.


Anyway, glad you had a good trip - thanks for sharing your mileage experience here.

The Honda Ridgeline looks like a macdaddy tow vehicle for a trailer in the 4000 to 4200lb range.
__________________
Dennis

"Suck it up, spend the bucks, do it right the first time."

WBCCI # 1113
AirForums #1737

Trailer '78 31' Sovereign

Living Large at an Airstream Park on the Largest Lake Totally Contained in Texas
Texas Airstream Harbor, Inc.
87MH is offline   Reply With Quote
Old 06-06-2006, 01:48 PM   #9
3 Rivet Member
 
Toasty's Dad's Avatar
 
2004 16' International CCD
Cincinnati , Ohio
Join Date: Nov 2005
Posts: 119
>I would further say that your engine was operating efficiently and therefore was >able to produce an extra +/- 20% mileage increase for about a 10% price >differential in premium vs regular gas.
>
>The BIG question is whether or not it will be able to do the same thing 150,000 >miles down the road.

Oh probably not, but you've made me a happy man today, Dennis.

Thanks,
jon
__________________
Toasty's Dad is offline   Reply With Quote
Old 06-06-2006, 02:07 PM   #10
Naysayer
 
Boondocker's Avatar

 
1968 24' Tradewind
Louisville , earth
Join Date: Jun 2005
Posts: 4,635
Images: 7
Send a message via Yahoo to Boondocker
So how do you tell?

How do you tell if your motor is capable of benifiting? Is it a safe bet that an old (1991) 302 will not?
__________________
Rodney

Visit my photography page
and the
Favorite camp grounds project map
My Blog

(The artist formerly known as General Disarray)

Boondocker is offline   Reply With Quote
Old 06-06-2006, 02:18 PM   #11
Rivet Master
 
Alumaholic's Avatar

 
1966 24' Tradewind
Albuquerque , New Mexico
Join Date: Nov 2005
Posts: 1,751
Images: 33
Click and Clack Say...

Click and Clack, the "Car Guys," advise that all "other factors" being equal, using premium fuel will not improve fuel economy. Otherwise, they reiterate, some of the advice given in this thread, i.e. if the car manufacturer says you must use premium, you must use premium or risk damage to your car's engine. You will not hurt an engine designed to burn regular by using premium, but you will be wasting money.

Toasty's Dad must have had some "other factors" contributing to his reduced fuel consumtion. This happened to me once the week after I purchased my 2003 Z-71 Suburban 5.3L with 3.73 differentials. I got 14.7 miles per gallon towing our 2000 Safari 27 from Albuquerque to Benson, AZ. I was delighted with my purchase, but it never happened again.
__________________
Ken L
1966 Tradewind 24
2007Chevy Silverado 2500 HD Duramax/Allison
Four Corners Unit WBCCI #8654
Alumaholic is offline   Reply With Quote
Old 06-06-2006, 02:25 PM   #12
Rivet Master
 
Wabbiteer's Avatar
 
1973 27' Overlander
1972 29' Ambassador
St. Paul , Minnesota
Join Date: Apr 2006
Posts: 1,912
Images: 2
Blog Entries: 2
yakkity yak blah blah I seemed to have written a book blah.

My daily driver & tow vehicle is a 1999 F150 4x4 5.4L auto with 87k miles.

Minnesota has mandatory 10% ethanol and I loose 12% highway driving with ethanol blend so I'm sensitive to mileage. With zero petroleum deposits in the state Minnesota will still have some fuel if the pipelines shutdown tomarrow so we grudgingly support ethanol; nowadays the discount for alcohol blend makes our fuel prices "appear" a little less painfull too.

When I get out of state and my highway mileage of ~15mpg goes to ~17mpg with less oxygenators added (ethanol) I try and find gas stations that have a competitive price and narrow spread between fuel grade prices and fill up with premium if it is not labled "ethanol added". My mileage jumps to ~19+ if I ease back out onto interstate, blend smoothly and drive the tank empty.

17 to 19 is nearly 12% so if the premium for premium is below 10% I can usually save money burning premium. At $2.80 a gallon for regular 87, 91 octane (ethanol free) for $3 would be a deal for me.

Towing my AS at 55mph and smooth higway driving gave me almost 14mpg using premium - I started calculating dollars per mile and saw a spread between $11 to $17 dollars per hour cruise with speeds & fuel octane changes. Hate being an obstacle in the right lane but money is too tight to be fuelish, just smile and wave like its great fun and get even at the fuel pump.

One thing it DOES do nicely is reduce (change) engine vibrations, lowering the engine shake amplitude lowers my fatigue level when driving straight through on long trips. I have severe tinnitus and being trapped for hours in a moving vehicle irritates tinnitus untill its pure misery - additional sound like radio or wind whistle stiffly lowers my stamina, burning premium is somewhat soothing over road-trip of 1200 miles (drive 6 / sleep 2 works well for me coast-to-coast)...
~
__________________

Wabbiteer is offline   Reply With Quote
Old 06-08-2006, 04:34 PM   #13
_
 
. , .
Join Date: Dec 2004
Posts: 8,812
hi fuel sniffers........

most owners manual will specifiy octane rating.......which dictates fuel type.

the audis for example specifiy 91-93 so premium is the ticket....using lesser octane rated fuels doesn't hurt short term (because the drivetrain will retard timing as the octane rating goes down....but hp and mpg decline too.

toasty/gen disarry......we are waiting 4 ya hat the rally!!
lookin g in your owners manual for the answer.

now the bigger issue is what about after ethanol is mandated in fuel......

premium will NOT have ethanol added while retualr does.........

cheers all
2air'
__________________
all of the true things that i am about to tell you are shameless lies. l.b.j.

we are here on earth to fart around. don't let anybody tell you any different. k.v.
2airishuman is offline   Reply With Quote
Old 06-08-2006, 05:28 PM   #14
Naysayer
 
Boondocker's Avatar

 
1968 24' Tradewind
Louisville , earth
Join Date: Jun 2005
Posts: 4,635
Images: 7
Send a message via Yahoo to Boondocker
Quote:
Originally Posted by 2airishuman

toasty/gen disarry......we are waiting 4 ya hat the rally!!
cheers all
2air'
I head up in the morning
__________________

__________________
Rodney

Visit my photography page
and the
Favorite camp grounds project map
My Blog

(The artist formerly known as General Disarray)

Boondocker is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
maybe kevlar would help aluminauts Off Topic Forum 18 01-16-2005 06:05 PM
Vintage Advantage Newsletter??? Rick T Our Community 28 08-27-2004 03:33 PM
65 Caravel / Globetrotter Tires robandzoe Tires 6 05-06-2004 10:21 AM
Airstream Books & Articles hex Our Community 5 11-11-2002 11:09 AM
Pulling a Bambi with a Ranger? wallycox Tow Vehicles 42 10-17-2002 02:29 PM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 10:53 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.