Anyone get 20 mpg with 4.0L V6 ?

Did a trip to Vegas this weekend, was about 1000 miles round trip and used 2.5 tanks. Averaged 18 mpg on the first 1.25 tanks and 22mpg on the second 1.25 tanks, with an average speed of 70mph.

 

The estimate might be exaggerated a bit, but I don't think that anyone can argue that gas mileage is much much better with non-ethanol fuel. I used to use premium unleaded in my 93 Saturn before ethanol and I was averaging 35 mpg. When they started adding ethanol in California fuel it dropped to about 31 mpg. Also, ethanol tends to evaporate or burn more quickly when it takes you 3-4 weeks between fill-ups.

I put premium in my truck when I'm towing. I've noticed more power and improved gas mileage over regular unleaded.

 

I never said there was no benefit to non-ethanol gas , I said I have a hard time believing he gets 8-12 MPG better mileage than every other 4.0 V6 owner on the site

 

Others may doubt that it's even possible to get 30mpg from a prerunner V6 but I'm sure it is possible.

With my I4 rated highway 25 mpg I commonly see 35+mpg during extended driving at 60 on the interstate. No reason a V6 rated 4mpg lower at 21 highway couldn't get near 30 mpg.

What I don't buy is that without changing anything else you went from 22 to 30 mpg.

My experience with non-ethanol vs ethanol is about 6% lower mpg with ethanol. 22 to 23.3 would be expected with no other change.

 

I can understand everyone's disbelief but that's what im getting. I see its alot higher than any other 4.0. What I did a year ago was 1.clean and reoil K&N air filter 2.run tank to almost empty 3.add 1 can Sea Foam 4.Fill tank w/non-ethanol gas 5.run tank empty again and refill. I fill up every time when the tank reaches a half tank until completely full and check mileage ever time(just a thing of mine). When my son drives my truck I loose about 2 miles to the gallon. He obviously drives faster than I do. The formula I use is miles driven divided by the gallons used each time to fill completely up(cant get anymore in tank). Basic math. I use the (B) trip meter to keep track of my mileage and zero it every time when I fill up. There ya go, bottom line. Thats what I did to the vehicle. If I did something wrong in the equation im sure you will let me know. And I drive between 55-60 mph which I used to drive 65-70mph.

 

Full highway tank I can come close...like 19ish. Before the lift I think the best tank I managed on my cross country trip was 21.xx

 

So you're averaging 300 miles for roughly 1/2 a tank everytime ?

 

Yes, I am.

 

on my access i only get 14-15 even with a K&N cold air intake.

 

back when i was stock yeah! those were the days.. haha.

 

When I fill it up until I can't get anymore gas into the tank I go about a 100 miles when the needle is right on the full mark. In other words the needle goes above the full mark when I fill it up.

 

I realize that

 

Wouldn't refilling at the half mark kinda skew the calculations in favor of highe mpgs? By watching my UG, my avgMPG is always highest right after fillup and it slowly decreases as gallons are used. At half a tank, I can expect my mpg to drop by at least a few tenths, at minimum.

No matter what, 30 mpg in a V6 is hard to believe, at the very least. I got 30 in my 4cyl camry only on long highway trips.

If you have a scangauge or ultragauge, your instant mpgs must be hovering around the 40s or 50s. Averaging 30 you must have very high highs to bring up the low mpgs you get at startup, stop signs, lights, etc.

 

It shouldn't effect the mileage that much if it's miles travelled divided by gallons used , in fact the truck gets lighter as gas burns off , so wouldn't it make more sense to actually get better mileage toward the bottom of the tank ?

 

That's impressive. So you are topping it off? Pumping more after the pump clicks off automatically? I can get about 60-70 miles to the full mark.

What model truck do you have? What mods? What brand/size tires do you have?

 

It's all in his specs

Doesn't overfilling contaminate the filter in the gas stem ?

 

Makes sense. I was thinking the more data points, the more accurate the calculation.

Still, I'm guessing low instant mpgs ~10-12, highs have to be reallly high. Only way to get that average up is long miles at consistently high, 35-40+ mpgs in order to average 30.

My low instant mpgs are 8-10 usually. Cruising the interstate my instants hover at ~30 @ 65 mph. It isnt until he end of my 16 mile trip before I get to my average of 23-24.

 

Just trying to wrap my head around it. Not questioning the validity or truth of it.

I could get 30 if I drove 45 everywhere. I can get over 100 mpg on a virago or rebel, again by going slower.

 

I have an 08 sport DC V6 auto with a 2.5" lift and running 70R/17 tires(32"). In the summer I average 19-20 with some around town and 55-60mph highway crusing. Haven't had it on the freeway at 70 or so for an extended trip so I can't say what my mpg would be there.
I run premium because it's only a buc or two more for a tank full and I notice that it pulls hills better and shifts smoother with it.
30 mpg would be great, but I'm really skeptical. I would think maybe 24-25 realistically. Reason being, with my stock tires I noticed the speedo was off compared to GPS. Didn't check the ODO. This would affect mpg calulations. With my current tires the speedo in right on. I fill till the pump stops, then add 1/10 more and calculate miles/gals. It's been pretty consistant so far.
By the way, my tires are C rated and I run 35psi rear/40psi front. This helped bring my mpg's up along with easy takeoffs and coasting to stops.

 

This I believe. With VVT-i you get the best performance from premium. You'll pay about $5 more per tankful with premium, but you'll get better MPG because of the increased HP and torque.