fuel economy

[DonL]

I suppose that if I have to ask, I shouldn't own a Lincoln----but, can I burn regular gas in my Aviator without harming the engine? Fuel additives that would help?
What is everyone else doing>
Don L.

[Bill's89LSC]

If it doesn't say "use premium gas" on the fuel gauge or the owners manual says to run regular unleaded go with that. Running a premium gas in a car that's stock is like throwing your money away. The factory set the vehicle up to run a specific gas when it left the factory and the window sticker would have given you (if you bought new) the EPA stats on it with the gas it was recommended for.

Bill

[Nick]

The DOHC 4.6L engine probably requires premium in the Aviator. It does in our newer Continentals. You could run something lower than 91 octane, but you will experience decreased performance and sometimes gas mileage as the engine computer tries to compensate for the lower octane gas by reducing spark. Just make sure the engine has a knock sensor before trying to run lower than recommended octane. I think 87 has been shown to decrease fuel economy and performance in the Mark VIII, but 89 seems like the lowest you can go without a big performance drop and a big fuel economy decrease. I'd run 91, but if push came to shove, I'd try 89 and crunch numbers to see if there was any actual savings.

[pro-five-oh]

I use 89 in ours. It will detonate when I drive it sometimes (I have a lead foot) but since my Mom drives it most of the time it seems fine.

It gets better fuel economy with premium, but not much better. I am very surprised at how thirsty this rig is. Its sucks down a lot more gas than our old 5.0L Mountaineer.

[Nick]

quote:Originally posted by pro-five-oh:
I use 89 in ours. It will detonate when I drive it sometimes (I have a lead foot) but since my Mom drives it most of the time it seems fine.

It gets better fuel economy with premium, but not much better. I am very surprised at how thirsty this rig is. Its sucks down a lot more gas than our old 5.0L Mountaineer.

You try being the slightly pudgy kid trying to haul a couple hundred pounds of sound isolation and electronic crap in Houston heat and you'd be a little thirstier too. :D

So the verdict is, if you are a lead footed driver, 91 is the way to go. How much is it for premium in Texas? We pay $2.18 for 91 here. It's $2.20 for 93 and 87 was $2.

[pro-five-oh]

Its about $2.09 for premium here. No biggie.

Another problem with the Aviator is that the 5-spd tranny spins the motor to 3000 rpm or more at part throttle acceleration. 2nd gear is very short. You cant get good economy with such an aggressive transmission. The older models were lighter, but their gearing and torque was also better suited for economy. (probably)

[Nick]

$2.09 is cheap, relatively speaking. You would think you'd get a better deal with the oil fields in Texas.

[pro-five-oh]

Maybe if Walmart owned the oil supply chain we'd be so lucky. ;)

[Steve L]

My Penzoil stock went up three times yesterday. I bought 3 more cases. :D

[Desert Stallion]

Y'all suck. We have 91 as our premium, and it's like $2.31 a gallon right now. :rolleyes: I don't even want to think about how much the Sunoco racing fuels are.

[Julesh]

quote:Originally posted by Nick:
The DOHC 4.6L engine probably requires premium in the Aviator. It does in our newer Continentals. You could run something lower than 91 octane, but you will experience decreased performance and sometimes gas mileage as the engine computer tries to compensate for the lower octane gas by reducing spark. Just make sure the engine has a knock sensor before trying to run lower than recommended octane. I think 87 has been shown to decrease fuel economy and performance in the Mark VIII, but 89 seems like the lowest you can go without a big performance drop and a big fuel economy decrease. I'd run 91, but if push came to shove, I'd try 89 and crunch numbers to see if there was any actual savings.

I agree with nick. You are supposed to run 91 or higher, it says so right on the gas tank cover. I often times run 89 and don't notice a difference. Think of it this way, you will pay less for 89 than 91, but it won't get you quite as good gas mileage or performance. I don't even think they have 91 around here, its 93 octane, so sometimes I let the tank get halfway, fill up with 89, then next time its halfway, I fill up with 93.

[Desert Stallion]

It really depends on the individual motor I think. My VIII is perfectly content to get around on 89, pulls down 22mpg in town and 27-ish highway for the short jaunts I've made with it. Would like to get it out and make an actual trip with it to see just what it would stretch out to, but oh-well.

Now if I know that I'm gonna thrash on it a bit, like if I'm going to the track, then I put 91 in, but that's few and far between.

[Don in Corpus Christi]

Well, I ran several tanks of 89 and 87 octane without much of a problem. Yesterday I put in a tank of 93 octane and my gas mileage has gone up to around 20 mph. I haven't had this kind of mileage since my Aviator was new. Usual mileage is 18 mph. dhl

[Rinkopr]

Let's do the math provided with the information given...

35 gal tank size just for fun....

Regular Gas @ $2 per gal that is $70 and the report says it gets 18MPG
Mid-Grade @ $2.10 per gal that is $73.50
Premium @ $2.20 per gal that is $77 and the report says it gets 20MPG

35 gal x 20MPG = 700 miles to empty
35 gal x 18MPG = 630 miles to empty

To reach the same distance with regular gas you would need to buy an additional 3.8 gals that equals $7.60 which means you will save $.40 by using the Regular gas over the premium which is what the engine was designed for when created.

Keep in mind I am only using the numbers we have had reported here, and just thought I would put a twist on this debate. I feel the mechanical costs that MIGHT (only a chance) occur out weigh the cost savings by using the cheaper gas. Just consider it a gamble. It may not give you problems for thousands of miles, but what will things be like at the 100,000 mile mark?