What grade octane do you out in your X?

[diablo5969]

I use the lowest grade, 87 I think, in a 4.0 OHV with 90,000 miles.

 

[Rob_B]

I use ethanol blend 89. I've never used 87.

Oh yeah, I have a 98 sport w/ the OHV engine.

 

[iugoodfella]

Im pretty new to all this lingo, what is pinging?

 

[Robert]

Throw a handful of b-b's into an empty, metal coffee can and shake it around. That is what pinging sounds like, only it comes from your engine.

 

[iugoodfella]

Ah nice visual thanks Robert...

 

[Mustangc1923]

i use 93 every tank and also add the octane booster and fuel treatment

 

[DarkFox1]

87 here.. 5.0s have an 8:1 compression they are designed for low octane applications, 93 would be "bad" for it according to the tightwad dealership. but I'm not complaining about the octane, who can afford 93 these days I mean its near $2 a gal.

 

[Robb]

Citgo Regular, 87 - used it for years

Little over 100K miles.........no pinging, no problems

Robb

 

[andypinto]

I always use 93 in my stock 4.0 OHV and now the engine get his 157K with no problems.

Andy

 

[Big Bear Bob]

I've been driving up a very steep grade on the back side of Big Bear Mountain. It starts at or near 3000 feet and at the top we live at or over the 7200 foot mark, the road is like a snake, and is very steep. I would guess you gain 4200 4300 feet in under 4 or 5 miles. The road has hair pin turns that some marked down to 5 mph, most at 10 and 25 MPH. Every time I've used 89 octane the climb seemed easier to pull and I don't have to keep my foot to nailed to the floor. Every time I've used 87 octane it feels like we're dragging something behind the truck, So I guess I am going to stick to 89 octane, might try 91, but there is a big diffeence in the way the truck pulls up the hill

 

[97emerald]

I have been using 87 in my 97 SOHC 4.0. I do get some mild pinging under light to moderate loads. I've only owned the EX about a month. Do you think cleaning the MAF would eliminate the pinging? I've read the threads regarding this and intend to try it.

 

[X24]

I thought the SOHC's had ping sensors that reduce the timing instead of pinging.

 

[Dan Whitaker]

I use 89 im my 97 5.0 it runs better with it as aposedto 87. I wish they would go to corn sqeezin's here. In Iowa the 89 is cheaper than 87.

 

[rydinhigh]

lets see I use 87 or 89 octane in my 95 4.0 ohv. about every three months i run my X down to empty then go get about 5 gal. of 103 octane. then I drive around town normally untill its time to fill up. the reason for the 103 octane every month is to basically clean the fuel system. I found it has worked alot better than those crappy stp fuel blah blah crap.

Another thing for those of you using octane booster please stop. its completely pointless. lets say you run 91 octane and the octane booster you bought says it will raise it 5 points. then you get 91.5 octane. kinda silly spending $10 a bottle if you ask me.

 

[Kadarom Douhrek]

Cheveron 87.
Cheapest around here and it makes the truck happy.

 

[MikeTEC]

Dan: I tried a tank of 89 in my 5.0 Limited and I, too, was surprised how much more pickup, ect..it had, plus the tranny seemed to shift more smoothly. I will probably switch back to regular in cold months. I will definately will always be towing with 89 octane, however. Mike

 

[Mike[socal]]

5.0s have an 8:1 compression

Manual says about 9.1:1 compression on my 99.

8:1 sounds awfully low unless you're pushing 15-20lbs.

I could be wrong though.

 

[Robert]

'98 Owner's Manual states 9.0:1 for 4.0L OHV and 5.0L V8, 9.7:1 for the 4.0L SOHC. 8.1:1 is too low.

 

[aldive]

Originally posted by Robert
'98 Owner's Manual states 9.0:1 for 4.0L OHV and 5.0L V8, 9.7:1 for the 4.0L SOHC. 8.1:1 is too low.

Ditto, '99.

 

[DarkFox1]

9? thats rather high to be running 87 octane, I could have sworn the 5.0 was rated at 8.0 and the mustang 5.0 at 8.5 oh well, apparently I'm the dumbest human being on the planet today, everything that I've been saying since I've got up has been wrong