Engine choices?

[Mr Big]

Question. Is this with the auto stop/start feature on? Also, is this real inner city driving, many stop & go's re lights etc (Think urban/metro type cities)

I get about 13 mpg city driving (alot of stop and go, with auto stop/start feature OFF)

My mileage is in FLAT Tampa Bay, with many traffic lights. I drive in normal mode, auto stop/start off, coast to red lights and take off normal. I'm never in a hurry as the lights are timed and you end up stopping more when you catch the light. highway-wise, I travel at 70 to 75 on Interstates and the speed limits on state and federal highways. This is all with 87 octane and normal mode.

 

[Mr Big]

I per example don’t see it that way, I think 87 Octan gas with Ethanol is inferior to 91/93 without it.

From searching several auto fuel articles:
Most higher-octane auto fuels have MORE ethanol in them, unless it is specified ethanol FREE. This is because ethanol is a cheap way to increase octane.
MUCH Older vehicles may have issues with ethanol in the gas. But newer cars that specify 87 octane gas don't, as they have changed the hoses, etc., that had issues with ethanol.
There is little to no benefit in using a higher-octane gas than what is specified for your vehicle, under normal driving conditions.
Examples of ethanol gas vs. no ethanol:
Midgrade and premium fuels, such as 91 or 93 octanes, are simply 10% ethanol mixed with gasoline, along with other petroleum compounds.
Some higher-octane auto fuels will advertise ethanol free. One example is Shell V-Power NITRO+ Premium Gasoline advertises ethanol free.
Wawa's in my area has ethanol free pumps, along with 3 octane levels from regular 87 to higher octane, which all have less than 10% ethanol added.

 

[Woodwolf]

From searching several auto fuel articles:
Most higher-octane auto fuels have MORE ethanol in them, unless it is specified ethanol FREE. This is because ethanol is a cheap way to increase octane.
MUCH Older vehicles may have issues with ethanol in the gas. But newer cars that specify 87 octane gas don't, as they have changed the hoses, etc., that had issues with ethanol.
There is little to no benefit in using a higher-octane gas than what is specified for your vehicle, under normal driving conditions.
Examples of ethanol gas vs. no ethanol:
Midgrade and premium fuels, such as 91 or 93 octanes, are simply 10% ethanol mixed with gasoline, along with other petroleum compounds.
Some higher-octane auto fuels will advertise ethanol free. One example is Shell V-Power NITRO+ Premium Gasoline advertises ethanol free.
Wawa's in my area has ethanol free pumps, along with 3 octane levels from regular 87 to higher octane, which all have less than 10% ethanol added.

hello Mr. Big: my Mechanic tells me that Ethanol is hygroscopic and that I, being retired, with low yearly mileage, would be better off in the long range using Top Tier premium gas, especially as the Expedition 3.5 engine is prone to carbon build up. As far as the ethanol mentioned is concerned, my Platinum stays idle for days at a time when I am at my fishing cabin which fosters build up of snod. I err on the wrong side?

 

[JExpedition07]

A lot of OEM engines are octane limited these days with the higher cylinder pressures. For example, the 5.0L V8 in my 2023 F-150 is running a 12:1 compression ratio (this is the same compression as the Ford FR9 NASCAR engine which runs race fuel). You can see in real time the ECU pulling timing off to avoid detonation on 87 when you throttle up. The 400 HP that Ford advertises for the 5.0L V8 is on 91 octane, but it makes over 400 HP on 93 octane, and it makes 420 HP on E-85 (101 octane). On E-85 the 5.0 actually puts over 410 lb ft of torque to the wheel so it’s making a whole lot more than 410 lb ft at the crankshaft that is claimed on 91 mid grade. They generally pick a fuel type to quote figures, but with high compression in the case of natural aspiration or in your guys’ case forced induction you can just keep advancing the ignition timing and further retard your intake cam to increase cylinder pressures and make more power. They will make more power up to around E-40 on stock mapping. Anything more becomes waste without cams or tuning.

 

[Fastcar]

I gotta point out what I feel people are missing. It is a TRUCK! As such it has the aerodynamics of a brick. It isn't going much faster. Want to go fast? Pick up a car and mod it. Of course you won't be able to tow much or tow very far. Enjoy it for what it is.

 

[mtrosclair]

I gotta point out what I feel people are missing. It is a TRUCK! As such it has the aerodynamics of a brick. It isn't going much faster. Want to go fast? Pick up a car and mod it. Of course you won't be able to tow much or tow very far. Enjoy it for what it is.

Engine power is important for towing and my turbo "brick" is pretty fast. This thread is more focused on actual measurable differences in power produced for a given spec engine and how those may be affected by using different grades of fuel.

 

[SyndicateZ]

I use 93 all the time (and I never tow and drive normally and easy on the acceleration). I only use 93 in the thought that its overall better for the engine and burns cleaner, helping keep things "cleaner". I dont use it for HP gains. Am I wasting my money and should I just stick with 87? Any real facts on the benefit of using a higher octane fuel for any reasons other than a few more HP?

 

[Left Coast Geek]

hello Mr. Big: my Mechanic tells me that Ethanol is hygroscopic ...

afaik, thats a bit of an old wives tale... 5% or even 10% ethanol, the hydrophobic (water repelling) properties of the gasoline will overpower the hydroscopic properties of the ethanol, the net mixture remains highly hydrophobic.