How does the 10'er perform with lower octane fuel;
Milege I would think 2 or 3 mpg drop?
Also overall performance?

 

With a fill up costing any were from $90 to $100 with 87 octane.

The choice is easy for me. Let it ping , let it ping, let ping.

 

My '08 does not like our 86 oct regular. Doesn't ping, but no power. The 88-89 oct midgrade is much better.

I talked to a friend that said his 5.4 really liked premium so Iv'e been trying it. Not enough time to tell for sure but it looks like the premium is giving enough better mpg to more than pay for itself.

Testing will continue. Your results may vary.

 

I think that will probaly be the case.
Thanks for the response.
Carry on.

 

I was running 93 in my 01 V10 but I finally replaced the fuel filter and then the O2 sensors in hopes of fixing this. On 93 octane I got no ping and 12mpg. With new fuel filter, O2 sensors and 87octane after two tanks of gas, no ping and ~14mpg. I used the bosch sensors with ~16" wires. Easy swap out, all you need is the sensors and the right size wrench, lay under your truck and replace. The passenger side would be hard for someone with shorter arms (I'm 6'4" and could barely reach the clip for the wiring with one hand). I have ~$110 in the sensors and $10 in the filter plus release tool for another $5.

If you're running 87 and it is pinging like mad, you are likely getting much worse gas milage than if you ran the 93 and had no ping. I had previously gotten ~14mpg with 87 and then went to 91 and 93 as the pinging probably required. I kept milage up most of that time but it finally started falling off. I would recommend either figuring out how to get rid of the ping or paying the 20-30 cents a gallon extra for the 93. Either way you will have a lot more power and most likely better gas milage. When you get low teens for gas milage a single MPG is a significant cost savings. Here is an example using current prices of the station by my house:

93 octane $3.89/gal
87 octane $3.55/gal

If you get 14mpg with 93octane that costs you $0.28 per mile
If you get 12mpg with 87octane that costs you $0.30 per mile

 

P.S.

If you are running a stock tune and everything about your engine and emissions is in order the 93 octane is not going to help milage, it in theory should only drain your wallet.

 

Juterbock,
I take it these numbers are based on the 2001 4x4 in your sig line is that correct?

 

Mmaxed, what kind of numbers MPG are you seeing on your ride?

 

87 vs 93 with stock tuning is a waste of money. Getting 2mpg better on 93 sounds like BS to me, but if thats the case sounds like the truck has problems. Custom tuning should be looked into. I've run 87 from day one on my truck with no pinging even when towing.

 

I agree with those that say 93 is not needed with a stock tune. My rig may have a problem or may not be broke in good yet with 9300 miles. Maybe we are just getting summer time fuel. There is no doubt however that the higher octane fuel is netting better performance, especialy at cruise rpm, and better milage at the pump. No pinging no matter what fuel is in the tank.

On the 88 octane I was getting 10.5-11.5 mpg. The last tanks of 92 have yielded 12-12.5.

Where I really notice the perfomance is pulling hills. On 88 the rig would have to downshift or at least come out of lockup to maintain the set speed. Most of the time with 92 it just cruises over with no trouble. The engine even has a different tone. A cleaner, crisper, healthier sound as compared to a dead blaaaaa on the 88 oct.

It could be that whatever the computer uses to sense pinging is over active and pulls the timing to much on this rig. It will be going to the dealer for a checkup when I get the time.

 

Hopefully they can tweak a 1 or 2 MPG for ya.

 

The milage I reference is the 01 4X4 with a stick and a lead foot. I had problems, and I have finally figured them out. New O2 sensors and a fuel filter have brought me back to the 13-14mpg with 87 octane.

 

Good to hear. 93 octane is like $.30+ more a gallon than 87, it adds up quickly.

 

Good info Right On!

 

Just to muddy the waters...

It used to be that, if you're vehicle was designed for, and ran ok, on regular, there was no benefit to using more expensive grades.

Now, (and here's where it gets messy) some brands of gas use 10% in ethanol in all their gas, some only in regular grade. Most often the pumps have a label that says "gasoline MAY contain 10% ethanol" so it is not easy to know for sure if they are using it, or in what grade.

If the place you normally fill up at uses 10% ethanol in regular, but not in premium, the decrease in MPG from the ethanol in regular, MAY undo the cost saving over premium.

As always, your milage WILL vary.
If you think you get better mileage with premium, you may be right.

Cheers,
jb