Nissan Frontier Forum banner

1 - 20 of 21 Posts

·
Registered
Joined
·
35 Posts
Discussion Starter #1
I've got a 2017 CC and it is flex fuel... not the reason I bought it at all, but was the color and options I wanted out of the choices available and just happened to be a flex fuel model. From the research I've done, the high octane burns so much faster that the money savings is moot. There's several stations in my area that have it and it is about a dollar cheaper a gallon. Any experience with it? Pros or cons to having it? Does it increase the value (price wasn't any more than similar non flex fuel versions)? From what I've read, it seems the fuel pump is larger and different injectors, but is that good or bad? I've never had a vehicle that ran flex and didn't really think much about it when I got the truck.
 

·
Registered
Joined
·
35 Posts
Discussion Starter #3
Will being a flex fuel vehicle make my gas mileage worse when running just regular fuel than the same truck that's not flex fuel? Or does that solely depend on the fuel itself. I've only ran regular gas and seem to average 17mpg... which, it's a truck so wasn't upset but even on a few road trips at highway speed didn't get any better than my daily commute travel mpg. The larger fuel pump design makes me wonder.
 

·
Registered
Joined
·
3 Posts
No.

Ethanol (C2H5OH) has a lower energy density than gasoline (a blend of hydrocarbons, which can differ somewhat), which means you get less kaboom per gallon of ethanol then from a gallon of gasoline.The benefit of E85 is lower pump cost-- around my area e85 is significantly less expensive than gasoline. If you are up for doing the math, it may well be the E85 is a better value proposition on a per-mile basis than the gasoline, despite the lower mpg.

When you run your truck on E85, your truck's EFI (Electronic Fuel Injection) system automatically adjusts the amount of fuel the injectors deliver, to perfectly mix with the air in the cylinder. It does this by sampling the oxygen content of your exhaust (your O2 sensor), the volume of air the engine is taking in (your Mass AirFlow sensor), and fiddling with the fuel amount until it hits the optimal stochiometric ratio to get a complete burn. This way the engine can electronically adjust to use different fuel mixtures, without requiring any adjusting by the operator.

So, what does that FlexFuel badge mean?

It means that your truck has proverbial guts of steel and can resist the corrosive effects of the ethanol, saving your gaskets and lines.


EDIT:
A small note about the sampling/adjustment rate. I do not know the exact value, but this link gives reason to think it's at several hundred times per second, probably more since our trucks are more expensive pieces of equipment than snow-mobiles (which is what the efi they're talking about seems to be used in).

http://www.efi101.com/forum/viewtopic.php?t=2866&sid=ed5905c3312288681272280c7f8af4af
 

·
Registered
Joined
·
2,143 Posts
So, what does that FlexFuel badge mean?

It means that your truck has proverbial guts of steel and can resist the corrosive effects of the ethanol, saving your gaskets and lines.
...And that the corn lobby has some serious political clout...
 
  • Like
Reactions: vjmvjm and Pacer6

·
Registered
Joined
·
202 Posts
E-85 is very high in octane so, compared to 87, more spark advance can be run in a high compression engine. I would sure like to try E-85 if I were you. The performance increase may be worth it.

Tt
 

·
Registered
Joined
·
35 Posts
Discussion Starter #7
Thanks for the input everyone. It's new to me!
I stopped and topped my tank off from half a tank and was smiling at the checkout. It did seem to run a little stronger. My wife had alot of errands out of the norm to run so wasn't able to gauge exactly test condition of fuel consumption plus I had my foot in it more than normal trying to determine how much meaner the engine ran on higher octane. I haven't had this truck really long so hard for me to determine base lines but I will try filling the tank with regular fuel, with just e85 and try a mix and track my mpg with similar work/home driving conditions over the next few weeks and post results here.
 

·
Registered
Joined
·
35 Posts
Discussion Starter #8
I checked the manual as i knew its not recommended to just switch over directly from one fuel to the other and if im reading it right, it says to start with with 5 gallons? So... I figure when tank gets to 3/4 tank regular gas then top off the 1/4 tank with e85, then top off again at half tank, then again at 3/4 tank would be the recommended swap over to run full strength e85??? I dont want to damage either my fuel system or sensors with extreme swings.
Btw... i average 17.2 mpg this week with a mix. I plan to top off next couple of fillups with regular gas to get the e85 completely out and get a baseline of my mpg under same driving conditions to get a true mpg on regular gas before switching it fully over to e85.
 

·
Registered
Joined
·
994 Posts
really? the manual says that? why can't I just got from almost zero to full with E85. I've done it once with no ill effects
 

·
Registered
Joined
·
35 Posts
Discussion Starter #10
I figured you could and topped a half tank and functioned great before i read that lol. It makes sense i guess to preserve sensors, injectors, computer system etc... its probably easier on the system to transition slowly but you would think an advanced system that takes constant readings of the exhaust burns, oxygen intake and adjusts the fuel injection it shouldnt matter. Probably alot easier on the cylinders and internal engine parts to ease into higher temps etc too.
 

·
Registered
Joined
·
250 Posts
Reviving this thread, curious what MPG guys are seeing with E85. According to the trip computer I seem to be going from 17 to 14 in mixed suburb type (35mph with stops) driving. Yet to get through a full tank to get an actual calculation. Power seems better than E10 fuel.
 

·
Registered
Joined
·
27 Posts
To correct one of the comments above, the manual says to switch fuels when you have atleast a 1/4 tank left and add ATLEAST 5 gallons of the new fuel. From the manual:

Your vehicle will operate on both unleaded regular gasoline with an octane rating of at least 87 AKI (Anti-Knock Index) number (Research octane number 91), or E-85 fuel, or any mixture of these two.

For the best starting and vehicle driveability results, do not continually switch between E-85 and unleaded regular gasoline. If you must switch fuels, NISSAN recommends the following:
● do not switch when the fuel gauge indicates less than 1/4 full
● add more than 5 gallons of fuel
● operate the vehicle immediately after refueling for a period of at least 5 minutes
I'm trying out E85 right now. Got a BlueDriver obdii plug and app that tells me the alcohol ratio in my fuel. Was getting ~2% on regular gas. So far I am up to 37% after 2 fill-ups when I have 1/4 tank left (22% after the 1st fuel up, 37.3% after the 2nd), so I think my local station's E85 content is probably just the minimum 50% (the sticker says it is between 50% and 77% or something like that), otherwise it would be jumping higher after each fill up. I'm also only saving $0.10/gal, so that also implies my E85 is only the lower end of the percentage scale. It does take a few minutes from the Alcohol content data point to update, so that driving for atleast 5 minutes after refueling makes sense. I don't have good MPG data yet. The manual says to expect up to 30% decrease, but that is what the government specifies, and in real world I hear it is less, closer to 15% because of the cooling effects of E85 on the charge entering the cylinder.
 

·
Premium Member
Joined
·
5,809 Posts
At 10 cents a gallon less, I'm not sure you will see savings. You are always going to have to compare the MPG hit or gain against the savings / loss per gallon of fuel. depending on, I've seen E85 10 to 20 cents cheaper a gallon all the way to over $1 cheaper. So, there would be times where it might be worth it.
 

·
Registered
Joined
·
7 Posts
how to tell if it's a ffv or reg unleaded only vehicle, besides the gas door? as there is no sticker on the door, 2019 cc v6 5AT thx..
 

·
Registered
Joined
·
202 Posts
I was in Indiana for business and filled the tank with E20 by mistake. I didn't notice a difference but my driving was all freeway.

2017 4 cyl. stick. not flex fuel.

Tt
 

·
Registered
Joined
·
205 Posts

·
Registered
Joined
·
1,753 Posts
As others have said, using E85 will cost you mileage. To compare mpg I filled the tank with regular unleaded or e10(10% ethynol) until pump automatically stops. Record your starting mileage, and when you reach as far down to empty as you feel comfortable, ecord your mileage again. I waited till Anita was below empty Mark before I filled up with E85. Again record your mileage and drive until you're at about the same position on your gas gauge and then do the math. You also have to be able to convert it to pennies per mile to really figure out if the cost is there for savings. I did so and I found that as long as the E85 is $0.50 less a gallon I'm coming out ahead. I personally lose about 1.5 miles per gallon using E85. I have also noticed when towing my camper at 4400 lb dry weight, I am better off using regular unleaded. Using E85 there is less power with E85 pulling a load. Good luck and let us know your results
 

·
Registered
Joined
·
6 Posts
I've got a 2017 CC and it is flex fuel... not the reason I bought it at all, but was the color and options I wanted out of the choices available and just happened to be a flex fuel model. From the research I've done, the high octane burns so much faster that the money savings is moot. There's several stations in my area that have it and it is about a dollar cheaper a gallon. Any experience with it? Pros or cons to having it? Does it increase the value (price wasn't any more than similar non flex fuel versions)? From what I've read, it seems the fuel pump is larger and different injectors, but is that good or bad? I've never had a vehicle that ran flex and didn't really think much about it when I got the truck.
Yeah when I first got my truck after a couple tanks of gas i filled up with e85 and it threw a check engine code
 

·
Registered
Joined
·
1,753 Posts
When E85 was. 40 a gal cheaper I would use it. Only lost about 1.5 mpg. Currently it's only about .15 a gallon cheaper. Not worth it at that price. Also it has never thrown a check engine light.
If it's about $1 cheaper, i would at least try it.
 

·
Registered
Joined
·
6 Posts
When E85 was. 40 a gal cheaper I would use it. Only lost about 1.5 mpg. Currently it's only about .15 a gallon cheaper. Not worth it at that price. Also it has never thrown a check engine light.
If it's about $1 cheaper, i would at least try it.
I was sayin that’s what happen to me the check engine turned on after I filled up I reset and over and over again it would keep coming back on. I don’t know why it was doing it, truck had 1k miles on it
 
1 - 20 of 21 Posts
Top