Carmelstev

I would have to disagree with using cruise to get better mileage. If you were on a perfectly flat highway, this might be true. On the typical highways we have in California with a lot of rolling hills and grades, cruise control uses more fuel by over-compensating to keep a steady speed. I find that my mileage goes down by a couple of mpg in all my vehicles when I leave it on regardless of the terrain. What I normally do is to use it over the flat terrain and go back to manual for the hills. I find that by speeding up slightly before the hill and then gradually bleeding off the speed on the hill, I get the best mileage.

Here's a section from a web site on hypermiling:



41) Constant throttle position cruising

Once up to speed, pick a throttle position and hold it.

Advantages: more efficient than using the cruise control (which varies throttle position frequently and wastes fuel on hills).

Disadvantages: less efficient than "driving with load" (DWL) / "target driving" (where the throttle is eased on inclines).



42) Cruise control - when to use it

Set the cruise control if you're the type of driver whose speed creeps up higher and higher the longer you're on the road, or if you have difficulty holding a steady speed (it wanders up and down).

But realize that cruise control is just a band aid for those behaviours. Generally it's less efficient than constant throttle driving, and much less efficient than "driving with load" / "target driving".



43) Cruise control - when not to use it

Only use cruise control on flat roads. On hilly roads, cruise responds to changes in grade - by feeding in more throttle on the uphill and releasing on the descent - in the exact opposite way an efficient driver would.

Steve

TPSTulane

Stay away from ethanol too, it drops your gas mileage also.

lxus4xms

Can you get 91 octane ethanol is the states? We can only get 87. The reason I ask is is the cold climate it is a good thing to run the (odd) tank of ethanol because it is so dry.

fangtl

Nothing to be ashamed of there, 23MPG on the highway is pretty darn good. The best I've ever gotten was 25MPG and that was on an I95 trip @75mph from Boston to DC.

TPSTulane

Some of the higher octane gas ( these days ) is being cut with ethanol to give the higher octane number... which will give lower MPG... but at the same time it is cleaner burning, and cleaner for your car.

So it's back to a case of pay now, or pay later.

It should be noted that OCTANE is NOT an ingredient. It is only a NUMBER. The number does not tell you what is in the gas. The number tells you how the gas behaves. Ethanol contains zero octane molecules, but has an octane rating of 110. E85 has an octane rating of 105.

lxus4xms

Great answer and thank you.
So when I buy ethonol up here in Canada its states that it is 87 octane, what do they cut it with to bring it down from 110? I always knew it was a good thing to run the odd tank of ethanol in the winter but please shed some more light on us. Thank You

TPSTulane

The standard "blending octane value" for ethanol is about 113. Normally one liter of ethanol blended with 9 liters of petro-gas raises the octane of the 10-litre blend to the next grade level. For instance after blending 9 liters of petro-gas with one liter of ethanol, Regular Unleaded (87 octane) becomes Unleaded Plus (89-90 octane) and Unleaded Plus becomes Premium (91+ octane). Consequently, marketers can often buy 89-90 octane Unleaded Plus ethanol blended gasoline for the same price, or less than they would have to pay for 87 octane Regular Unleaded petro-gas. In order to produce Regular Unleaded gasoline with ethanol, a blender must have access to an 84.5 octane (or "sub-octane") grade of petro-gas. In some markets sub octane gasoline is not made available to blenders. In these locations, Regular Unleaded (the lowest price grade gasoline with the highest sales volume) does not contain ethanol. In markets where sub octane gasoline is available, however, ethanol blended Regular is usually less costly than petro-gas Regular.

GRAND_LS 4

iTrader: (2)

Did you account for wind factor? we've had lots of winds in Northern VA that was mostly likely working against you (coming from the north west).

I think that is one element people almost always overlook.