Ruthenium spark plugs anyone? E85??

[Tinker1980]

I've been running ngk ruthenium spark plugs since I got my mirage DE around 45k miles ago. I'm wondering though if I'd be getting better mpg just using the stock iridium plugs or even something more warm. Also has anyone tried E85, the fuel prices here in MD are crazy at $5+ for 87.

The Mirage isn't made to run on E85, it might sort of run on it, but it won't run right. Your best bet is the 87 octane.

I bought a truck back in January and it's the first flex-fuel vehicle I've owned, which gives me a chance to perform all sorts of experiments at my expense. It gets slightly worse mileage on E85, around 14 MPG or so driving around town, while on gasoline it gets more like 15.5 or 16. However, when gas costs $4.50 a gal and E85 costs $2.90 a gal... the E85 comes out noticeably cheaper over an entire tank. As for performance, the truck's engine pings a bit under load with 87 octane, but absolutely doesn't ping at all, ever, on E85, and it has noticeably more power. This is a 3.7 liter non-turbo V6 in a heavy-duty fleet version of an F150.

For the plugs, I don't think the plugs would affect the mileage a whole bunch unless they were causing the engine to misfire.

[7milesout]

However, when gas costs $4.50 a gal and E85 costs $2.90 a gal... the E85 comes out noticeably cheaper over an entire tank. As for performance, the truck's engine pings a bit under load with 87 octane, but absolutely doesn't ping at all, ever, on E85, and it has noticeably more power.

Wow. Yeah, if E85 is THAT much less expensive, I would run it in my (flex-fuel) vehicle too. I don't pay much attention to E85 costs because I don't have a flex fuel vehicle. But I think it is nowhere near that much less expensive than 87 octane E10, around here. I'll try to notice next fuel up.

However, I question your buttometer. If the E85 gets "more worseter" mpg than 87 octane, my instinct (which could be wrong) tells me the E85 should be yielding less power too. However, there could be an exception. If your vehicle is pinging / knocking on 87 octane, it could be retarding timing to lessen that and it will lose power due to retarded timing. It might be that you'd have to run several tanks of 87 to work the timing back to advanced. Or it could be that it may never run full advanced timing on 87.

But an interesting post, in any event.


7milesout

[sunbeam]

I've been running ngk ruthenium spark plugs since I got my mirage DE around 45k miles ago. I'm wondering though if I'd be getting better mpg just using the stock iridium plugs or even something more warm. Also has anyone tried E85, the fuel prices here in MD are crazy at $5+ for 87.

Do you have the part # or a link for the ruthenium spark plug you used?
If anyone knows what this part # is would appreciate it.

[Fummins]

look up spark plugs on rock auto for any year mirage 2014+
Part number is 96355.