Question about buying a New Chev. 3/4 4X4 Truck with Flex fuel.

[Wildbob52]

What does the dealer mean about Flex Fuel? This truck only gets 10-15 mpg. the company says but the Saleman says it gets 21 mpg on the highway because of the flex fuel. I've had six people tell me this truck is real gas hog because of the 6.0L engine.

Thanks.

[Yarcola]

Don't believe dealers. FlexFuel simply means that, in addition to "regular" gasoline, it is set up to burn E85 Ethanol (bio-fuel). You will actually get lower MPG with FlexFuel. The 21MPG rating is probably the highway rating for the smallest engine available.

However, the latest Consumer Reports reliability ratings do show the Chevy/GMC heavy-duty pickups as the only ones that get above average reliability ratings.

[okgc]

Don't believe dealers. FlexFuel simply means that, in addition to "regular" gasoline, it is set up to burn E85 Ethanol (bio-fuel). You will actually get lower MPG with FlexFuel.

X2
Your mileage will go down when burning E85 fuel.

I suspect the 21mpg is a Silverado with the 5.3-liter V-8 with active fuel management, which shuts down four of the eight cylinders under light driving.

[EZDZIT]

Our 2012 GMC Sierra K1500 extended cab with 5.3 liter engine in flex fuel but I don't bother with E85 even if it is available. As stated earlier, the fuel mileage with E85 will go down. We just turned 10,008 miles, not counting another 10,000 miles behind the motorhome which do not count on the odometer. The vehicle computer states the average for those 10,008 miles has been 15.0 mpg. I doubt we have ever seen a 21 mpg day but the otherwise we enjoy the truck.

[tuffr2]

E85 has less BTU per gallon than straight gasoline. Same as straight gasoline has less BTU per gallon than diesel. Most summer gasoline in E10 which produces less MPG than straight gasoline.

There is roughly a 20% drop in power from diesel to gasoline and another 20% drop to E85. So when you see E85 cheaper than gasoline by 60 cents per gallon it is not a bargin.

[jamesrxx951]

Originally Posted by tuffr2

E85 has less BTU per gallon than straight gasoline. Same as straight gasoline has less BTU per gallon than diesel. Most summer gasoline in E10 which produces less MPG than straight gasoline.

There is roughly a 20% drop in power from diesel to gasoline and another 20% drop to E85. So when you see E85 cheaper than gasoline by 60 cents per gallon it is not a bargin.

The drop in power with E85 is not entirely accurate. Some trucks are rated with higher HP when E85 is used. The truck obviously uses more E85 doing so but once the PCM determines that E85 is used, the calibration tables changes for that fuel. However E85 to me is a waste of money.

[SeabeckS]

The 6.0 GM motor is rated at 21 in a 1/2 ton Silverado/Sierra. 3/4 ton and higher are exempt from the EPA rating system, or at least, they have been exempt. Perhaps that has changed...

+1 on the E85 feedback. I've got a near "religious" fixation (LOL) on tracking fuel mileage in all of our vehicles and have done so or nearly fifty years. When the ethanol "enhanced" fuels became available it was easy to determine an approx 10% reduction in mpg with the 10% ethanol mix. Sort of tested my theory last year with a 4500 mile trip of mostly driving the super slab. Most of the time used pure gas, but twice tried the E85 stuff, true to form the mpg dropped about 15%. And even though the E85 stuff was a bit cheaper, when I computed cost per mile, E85 was a loser.....YMMV!

Cheers!

[Wildbob52]

Thanks for all the information. I'm thinking about buying a GMC 2500 4x4 truck from Carmax for 20,000 with only 9,000 miles. Engine also is a 6.0L. Dealer told me the 6.0L engine can go from a V-8 to 6 or 4 cylinder engine and wonder if this is true?

Bob

[onechaddude]

I had a 2008 chev crew cab 2500 with 6.0 v8 gasser for about 5 months and bought it new. I can tell you for a FACT it will not get 21 mpg in any driving you do. You can't coast down a mountain and get 21. I am sorry if I burst your bubble but it ain't gonna happen.
Chad

[SeabeckS]

Originally Posted by Wildbob52

Thanks for all the information. I'm thinking about buying a GMC 2500 4x4 truck from Carmax for 20,000 with only 9,000 miles. Engine also is a 6.0L. Dealer told me the 6.0L engine can go from a V-8 to 6 or 4 cylinder engine and wonder if this is true?

Bob

I "think" the 6.0 engine is the Vortec, not the same as the 6.2 EcoTec V-8 that features the cylinder deactivation (8-6-4), buyer beware. Maybe an un-informed dealer? And just because it is a 2500, I'd be curious about the tow ratings. Have you looked at the door sticker to see the max GCWR for that specific chassis?

[TXiceman]

Flex-fuel means it can run on more ethanol in the gasoline than a conventional engine. More ethanol means lower fuel economy since ethanol has a lower heating value or heat content than does gasoline.

Some of the engines use cylinder deactivation to increase fuel economy on the road....provided fewer cylinders can push the beast along.

Ken

[tuffr2]

What year truck? Just an FYI - for 2011 chevy heavy duty trucks got a much better frame.

If the truck is 2011 or newer that sounds like a real good deal.

[Wildbob52]

This truck I'm buying is brand new 2014 model for 23,300.00 with my Trade-in 2007 Ford Escape Xls model and with 79,000 miles. They giving me 7,000 for my trade-in. The truck is a plain jane white work truck and it is 3/4 ton with 4x4 to pull a future 5th wheel camper. People are telling me I need a 4x4 truck to help pull a 5th wheel.

[Lightning83]

We use the E -85 for in town driving but not highway ... Seems to not make a big diff in mileage intown but def on highway ..... Big savings intown though ! For us at least. Reg price at top..... Diesel in middle...... E-85 bottom