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Fuel mileage difference using higher octane

9K views 18 replies 11 participants last post by  asimon12 
#1 ·
Has anyone done this sort of test with higher octane?
 
#2 ·
Using higher octane than the manufacturer calls for is in most cases is a waste of your money. Here is a decent summary of octane usage for you to read:

http://www.ftc.gov/bcp/edu/pubs/consume ... aut12.shtm

Note that there are a small percentage of vehicles that will perform better on higher octanes, but usually that has to do with the settings in your chip.

If you want better mileage, drive like it. You can go to sites that specialize in hypermiling/hypermilage, but be warned that it means you won't satisfy any urges to drive fast or fulfill your adrenaline needs.

Your best overall bet for decent mileage is to make sure that you keep your engine in the best tuneup condition and try to keep your foot out of acceleration. Truth. ;)
 
#4 ·
I have tried a tank of regular and a tank of supreme, a tank lasts me about a week. Same mileage both weeks at about 50% highway and 50% city. My MPG changed by .2 with the higher grade but that could of been because of another variable like temp, idle time, weather, ect. The best thing I have found that when accelrating from a stop if you keep the RPMs under 2k it will really help.
 
#5 ·
Well I dont believe this is the whole truth, with the ethanol they add to fuel. Non-ethanol fuel has been proven to yield better mileage. And the numbers I am getting so far with my rig this winter prove 91 octane is better gas then 87. I drive a 60/40 highway/rural to work with the cruise set on the highway at 60mph. I think this ethanol in the gas is total BS. All of them are in on it, car manufacturers, oil companies, big business. All of the go green stuff,now there is this sudden worry about ecology....one would think the automobile has been around a long time,long enough to have it all figured out on how to get 50 mpg in a truck and even higher mpg in a car. they know it can be done,will they do it...more than likely not. the rich would be a little poorer and the eco system would be cleaner LOL.

Thanks morpheus for that info, i am light on the pedal.
 
#6 ·
Ya Im not sold on the ethanol in fuel either. Might make a differnece on your truck though since its newer, mines an 04. I try to stay light on the petal too but its hard when a little highschool kid wants to race there ricer :lol:

Also consider your cost per mile, is it worth another 20 cents per gallon in the long run?
 
#7 ·
Well, there's no question that the ethenol reduces your mileage, that's just fact. It's also today's unfortunate reality.

And Morpheus is right; is the extra cost worth it to you? If you think so, then have fun and enjoy. You are not doing any damage to your truck. You also are probably not getting your money's worth for the extra octane, but it's your money and none of our concern. Drive on!
 
#10 ·
Back to the original question:

I drove a lot this fall using only 91 octane, since that's what my programmer was tuning the truck for. It was a nice kick in the pants, but did nothing for fuel economy.
 
#11 ·
starspangled6.0 said:
Back to the original question:

I drove a lot this fall using only 91 octane, since that's what my programmer was tuning the truck for. It was a nice kick in the pants, but did nothing for fuel economy.
The main reason for running higher octane is you can run more timing without the motor pinging. If tuned right and you keep out of it you will see a MPG increase but nothing worth writing home about.

I know with a K&N filter, home made tube, free flowing muffler and the custom tune if I was really nice to it I could break 20mpg with my 6.2
 
#12 ·
Well, it was only a canned tuner (Hypertech). I most definitely noticed a power bump from 87 tune to 91 tune, but the fuel costs never got recouped. The power was worth the extra $0.20\gallon, though :twisted:.
 
#14 ·
Ditto on the power! Just installed my hypertech today and drove to work. Man it really hauls now! Really got to watch my heavy foot now. will have to keep it below 2000 rpm and use cruise control more. Was it worth the power bump????? YES, Yes it was!!
 
#15 ·
So,Since our newer trucks can mostly use e-85 and the octane level on e-85 is like 115 and regular fuel is 87. Apparently our engine computer can tell between the two, So why wouldnt it be able to tell if you were running 91 octane. :?: Furthermore, I was thinking that Gm should start putting v4-v6-v8 selector switches in trucks. when im going stop and go in citys, i dont really need to get going in a huury. If i did need romp on it i could select v8 mode. :evil: Or if you are towing or hauling something. Most of the time my afm kicks in its an annoyance. Im really hoping that gm comes out with something that beats fords asses in hp and mileage. I am so tired of hearing about the ecoboost crap. Really gm had direct injection long ago. Also gmc had the turbo typhoon 4.3 liter v6. So im betting on gm laying waste to the other truck manufacturers. :twisted: Sorry soo long. :evil:
 
#16 ·
Well, if you have a recent 1500 with V6 or V8, it's likely that you already have active fuel management and maybe don't even know it. I know my 5.3L has it, which is why, I can sometimes rack up as much as 21 mpg when I'm traveling highway and can keep the heavy foot deactivated.

For those of you not familiar with active fuel management, here's a quick article:
http://en.wikipedia.org/wiki/Active_Fuel_Management

In other words, your truck may already be shutting down 4 cylinders while cruising and you can't even tell. :shock:
 
#17 ·
I have not been able to measure a difference in fuel economy when I have run mid grade gas. Only difference is a slightly smoother transition when it goes in and out of 4 cyl....I think.

In other words, not worth the extra $.10 per gallon.
 
#18 ·
Well I taken some advice from this thread and have been keeping the rpm's around 2000 when taking off from stop lights and stop signs.Also I change my route to work as well,mostly 45-50-55 mph speed zones with vary grades to the roadway. i topped it off last sunday with 91 octane, mid grade 89 was .5$ cheaper than 91. So far this week driving to work I have picked up 2mpg more than in the past barreling down the highway at 65mph. Crappy weather here in NY. In the 40's one day and the next it's in the 20-30's range.Not sure the octane had anything to do with it, more than likely my driving habits. averaging 18.2 to 18.6 mpg. My truck has a 5.3 six speed, regular cab with 3.42 gears.
 
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