It says to get @ least 91 octane in my '11 5.0. Can I just fill up with regular & use some octane booster stuff? Thanks!!

 

The car can adapt to 87, 89, or 91. You just lose some power and torque (around 10 I believe). But it won't hurt it all to run 87

 

I wish we had 91 here.

 

Don't care about losing power. Just thought up this while typing. I want better mileage, so I can afford to drive more each month. I get disability so I set back certain per month for gas. If I get less with 87, wonder if that will change up miles to 91 octane? Did I say that right? Might figure this up next month? Just filled up w/91. I get Walmart gas cause I put that $ into a gift card. That helps me not blow that $.

Thought I read it could ping running 87? I have no idea what that means!! Just doesn't sound good?

I can get by on $100/month & going less than 900 miles. Thanks!!

 

No problem Eli, it should run 87 with no issues

 

Cool! I just am not smart enough to do stuff if stuff acts up. I can't even say that right!

 

Hasn't this been covered a bazillion times

 

It's been said already, but I wish to add:

If you've been running <91, it may ping/knock a little on acceleration until it re-learns how to work with the lesser octanes.

You may also see, due to the 10 less HP/Torque as stated, a slight degradation in MPG. Mine, for some reason, equals about 1.5-2MPG less per tank. Perhaps I'm overcompensating, but I think it's more the retardation of timing causing it.

Please note, I have the 4.6, and it may be that the 5.0 won't lose as much MPG.

But as far as hurtin' anything? Nope. Go ahead and do it. The ping/knock will go away after about 2 tanks.

 

As has every other topic, and yet there are those of us who will help anyway, and those of us who will say something such as "hasn't this been covered a bazillion times.", and that has been the case for, oh, about a bazillion times too.

 

It's also false economy to run 87 and then try and make up the difference with octane booster.

 

I'm sure this has been talked about! I'm just not smart enough to remember to look on other's threads!! I barely can mine. Plus, after a while these start drifting from what I 1st asked. This way I can get the answer right off, then y'all can discuss other stuff. Sorry & thanks again!!

 

You may want to check and see if the Regular you are planning on using has 10% alcohol added. In the area I live in, Regular and Mid-Grade both have 10% alcohol.

I have found using either one results in slightly lower mpg. The premium is 100% gasoline according to the pump label, so I have been using it, and my mpg stays pretty steady. Last tank was 23.2, with mostly highway driving.

 

Kinda think all grades of gas where I get it is that way? Yeah, I have no real idea!! Seen a sticker somewhere, maybe?

Sorry, so if it is 10%, it's still OK to use. It just won't get as good perf & MPG #'s?

 

Yep..10% is the max thay are allowed to add to gas. The pump should have a sticker on it telling you it has "10% Ethanol", which is what they do here in South Dakota. I don't think performance will change that much (someone correct me here) but the mpg's do suffer with alcohol in the fuel.

I believe if you use regular, your Horsepower will drop to 404 from 412 (like I would notice). I read that some where, but can't recall where right now. I will check my files.

All in all you should run two or three tanks of premium and check your mpg. Then do the same with Regular and check the difference.

Hope this helps.

 

This is exactly what i've read about this topic.

 

Exactly as above. The manual even states it is fine with 87, but 91 is recommended for best performance.

Definitely don't run 87 and use octane booster. You won't save money.

Oddly enough, my car has gained fuel economy since I've been running 87 during the winter. But that could be a result of my granny driving in the pouring rain in the winter months.

This is the way to go, don't base your findings on a single tank. Run a few tanks of one grade and drive the way you normally do, then change to another grade and drive the way you nornmally do. But give more tanks on the 2nd method before comparing your results, so your car adapts properly to the new octane level.

 

I keep up with every penny I've spent on it. I have each gas receipt with mileage & I put my MPG. I have a notebook to write it all in. Just stuffing the receipts in the folder of it. I will average per month & stuff. Still thinking new ways up, so don't need to do it yet.

Next tank, 275-325 miles I'll use 87. This MTE said 278, we'll see.

SD CALSPCL; there's no need to find that exact #, for me.

 

I've gotten the same mileage from 87 and 93 -- 20 MPG even. I run constantly with 87 now and have NEVER gotten any pings/knocks/rattles/squeaks. Save your money unless you go to the track.

 

That's news go my ear!! & I didn't even plant this seed in my head. I was talking to a friend, he said about using an octane booster. I wasn't sure, so after 8 mths after buying only premium, I asked you. Better than forever I guess. Thanks!!

 

interesting . . . my 4.6 seems to get slightly better mileage on 87, but I like the way it runs on 93 better (I like that low end torque, I guess)