Thread: Increase the gas mileage...what works for you and your ride?

Well, here's my summary of it all after playing with different speeds and the additions of the K&N cold air kit, Hypertech programmer (set for 87 octane), and Flowmaster exhaust. The summary is that having a big SUV, combined with AWD, 6.0 liter engine, and running the A/C...average MPG local driving & keeping the speed under 65 mph is 13.5 mpg and highway between 65-70mph is 15 mpg. Basically my thoughts on saving some $ was a bust. I have a better sounding truck with more power. This is the first 6.0 engine that I have owned and it seems that no matter what you do to it, it loves fuel. I could have bought a LOT of fuel for what I added to it. So, in summary what works for a GM 5.3 v-8 does NOT work for a GM 6.0.

Now I am looking into a way to be able to turn from a AWD to a switchable 4wd...

I use very little gas period,living in a closed retirement community we roll on electricity

Tire pressure, manually cycling the A/C, and coasting when possible can add up to 4-6MPG in my experience.

Tire pressure is easy, the other 2 are tedious and require both conscious thought & dedication.

I can't provide any specs for this because I did the following with a 1981 AMC Concord I bought new off the showroom floor. I was pretty anal retentive back then and was nearly OCD with my gas & mileage records, but I can't remember specific numbers after all this time. I did verify that each action below consistently increased my gas mileage.

1) First thing I did was was to increase the tire inflation pressure to the max pressure stamped on the tire to minimize rolling resistance. I had Goodyear steel belted radials and never noticed a problem with tread wear.

2) The next thing I did was to try an oil additive I think I read about in Popular Mechanics Magazine called Tufoil. The main ingredient in Tufoil is PTFE, which is what Teflon is made out of. IIRC, Tufoil was in the Guinness Book of World Records for being the slipperiest substance on the planet. It definitely did increase my gas mileage, but it was winter starting that sold me on using it.

I lived in New England and worked nights so my car sat out in the middle of this huge parking lot, exposed to the weather all night long. Some January mornings I would get out of work at 7:00 AM with the mercury hovering at less than ten degrees above zero. I never put a stopwatch to it, but I swear, it seemed like it took 30 - 60 seconds of cranking to get that car to start on those cold mornings. Some time after that first winter was when I started using Tufoil. Like I said, it made a noticeable increase in mileage, but that following winter was when I was most impressed. No lie; adding Tufoil to every oil change enabled that car to start after cranking over just three revolutions on those same bitter cold mornings.

3) I don't know how much benefit (or even if) this next tip would have on a present day fuel injected computer controlled engine, but it really made a difference on that carburated engine my car had. I connected a vacuum gauge to the intake manifold and mounted it on my dash. When I drove the car (it had a manual transmission), I did my best to to consistently keep the manifold vacuum as high a I could keep it. It gave me immediate feedback to use a light touch on the accelerator pedal. I guess maybe it cut down on use of the accelerator pump too. (You young guys who've never worked on a carburator won't know what that is.) I doubt it helped much in stop and go city traffic, but my job was a 45 - 50 minute drive from home on long, straight country roads and that's where I did most of my driving.

4) I never did get around to trying this next one, but a friend got good results with it so I'll tell you what he did. He added a couple of teaspoons of Molykote (molybdenum disulfide) to his differential fluid and he swore that after it had a chance to mix in with the fluid, his car would coast "forever" in neutral.

It made sense that it would help because Molykote is a super slippery dry lube. I was planning to mix some Molykote with Tufoil and add that to my differential and manual transmission, but the house needed a new roof, and the basement needed to be waterproofed, and I had so many other projects in various states of completion that. . . .

Hey, if anyone tries that, I'd be curious to know if you find any benefit. My home mortgage takes the lion's share of my pension and we have good public transit where I live so I don't own a car at this time.

I leave my old '76 F250 ( running a 351 Clevo, 1/4 race cam and Holley 600 double pumper ) pickup truck in the shed most of the time and use my horse mostly. Lucky to do 1,000 miles a year, saves a lot of gas !!Not much help am I !!!!


Cheers

Heelerau