30 mpg more per tank

[cupton]

All of a sudden, for the past 2 fill ups, I am getting 30 more miles per tank of gas than I have been getting since I got the truck. Could it finally be broken in? Is it the Mobil1 that I switched to when I hit 6,000 miles? I now have 7,200 miles on the truck.

Just thought I would share some better gas mileage joy!

[KLS]

Different brand of gas?

[cupton]

I haven't changed a thing other than the oil.

[boody]

Your probably just learning to keep your foot out of it.

[kirker912]

I also just switched to mobil 1 and my gas milage improved drastically. I can tell by the gas gauge right now. I have only filled up once since I changed. I will have some definate numbers this friday.

[duke boy]

I've heard over and over again that synthetic oil helps gas mileage, but I don't understand how. I just don't believe it can make a difference. What is the theory behind it? Decreased friction?

[tempetom]

I wonder if colder air helps the mileage?

[bennicde]

Originally Posted by tempetom

I wonder if colder air helps the mileage?

nope, colder it is , the more gas you use.

[cupton]

I have no idea why I have gotten 30 miles more out of each of my past 2 tanks. I have been driving the same route to and from work since I got the truck and I haven't changed any driving habits that I can tell. We'll see what the tank I just filled up with today will give me.

[murfdaddy]

Maybe the gas is more dense since it's gotten cold.

[CATiger]

Enjoy the good fortune. I find that in colder weather, the denser air provides a slight increase in power, thus reducing the need to kick it out of overdrive on any of the grades I drive. I found that for my truck, this and other light-footed driving measures were enough for me to average about 1 mpg better with mostly highway driving when it's cool.

But there are too many factors to know for sure. It can't hurt to keep your tires aired up, a clean air filter on the intake, plugs and oil changed according to your maintenance schedule.

I think the value in synthetic is the extended drain/refill intervals. Even if you could equate a 1 mpg increase by swithcing all the fluids to synthetic (may be a reasonable guess, I don't really know), I feel the time it would take you to recover the additional cost would be too great for real consideration. Plus one tank of burn outs and stoplight drag races, and poof! there goes your savings. From what I've heard most engines when regularly maintained and generally well cared-for will outlast their owner's will to drive them, even with dino oil... imo. But again, whatever makes you sleep better at night is the most important.

FYI for me - Mobil 1 in the engine & amsoil syn everywhere else. Haven't missed a day at work or a wink of sleep because of maintenance on my truck.

[Misfit138]

I apologise if this is on another thread but what kind of gas mileage are you guys getting. Ive got an 06 DC with about 800 miles and I am seeing about 14.5 to 15 MPG and I haven't had the revs above 3 grand.

Thanks and sorry for the hijack

RK

[Shite2k]

I am willing to bet it is because you switched to synthetic oil. It is an attribute of synthetic oil's to improve gas mileage slightly.

My limited understanding of oils is that all oils are comprised of little molecules. Regular "dino" oils have molecules of all sorts of shapes and sizes, where as manmade synthetic oils have tons of little molecules all of the same shape and small size. This allows them to lubricate much better and get into and out of places as required in the crankcase.

I recall someone here posted a story about horsepower TV where they ran a dyno on regular oil and then swithced to synthetic oil and transmission fluid and gained 7 horsepower on the Dyno or something like that on a Camaro. It's because there is less friction in the oil which makes the car's job easier. It doesn't have to push oil around as much as it once did.

This is sorta related to why headers and/or exhaust also improve fuel mileage slightly. It's because they facilitate scavenging of exhaust gases much better which means when when one piston is on it's compression stroke, it doesn't have to use as much horsepower to help other pistons push their exhaust out. And so it goes into making the engine's work easier which translates to more efficiency, more power, etc.

[Nevadastars]

The synthetic may have something to do with it, but I'm betting it's mainly because you have more miles on it. The engine is starting to loosen up and spin more freely. I bet you could put regular oil back in and still have the same or close results as you are not getting. I know my wifes 03 V6 Accord was getting around 25-28 highway when it was new. After it reached around 10k, its started to get 30-32. We never put synthetic in it. My Tundra has too few miles (3400) on it to know how it will do later on.

[Bung Hole]

Shake this dude, he must have been dreaming to think he was getting 30mpg, that or he is just not good at math, probably has a defective calculator. must be a republican calculator.....