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-   -   Unleaded vs Premium for JK (http://www.wranglerforum.com/f274/unleaded-vs-premium-for-jk-278449.html)

TomJeepWrang13 09-06-2013 12:05 AM

Unleaded vs Premium for JK
 
Okay, so another question arose recently. My brother suggested I start using premium gasoline as opposed to regular unleaded for my new 2013 Jeep Wrangler Sport, because it'll be better for the engine and so forth. Now, I'm on a budget, and gasoline prices do not obviously care about whether or not people are a budget. So can someone please tell me if using Unleaded is okay for a new Jeep Wrangler. I've used nothing but unleaded in my old car which was a 4 cy. 2007 Toyota Yaris Sedan, which ran fine up until I traded it in. Thanks.

- Tom

DallasJKU 09-06-2013 12:07 AM

Quote:

Originally Posted by TomJeepWrang13 (Post 4333505)
Okay, so another question arose recently. My brother suggested I start using premium gasoline as opposed to regular unleaded for my new 2013 Jeep Wrangler Sport. Now, I'm on a budget, and gasoline prices do not obviously care about whether or not people are a budget. So can someone please tell me if using Unleaded is okay for a new Jeep Wrangler. I've used nothing but unleaded in my old car which was a 4 cy. 2007 Toyota Yaris Sedan, which ran fine up until I traded it in. Thanks.

- Tom

Waste of money

Raiderfan001 09-06-2013 12:08 AM

Your brother is wrong.

Makalohee 09-06-2013 12:11 AM

87 Octane is perfect. Save your money for mods. New engines are supposed to do just as well with regular as they would with premium anyway (or so I hear).

TomJeepWrang13 09-06-2013 12:15 AM

Thanks guys! :iamhappy:

mckey73 09-06-2013 12:21 AM

Pentastar Engines: Overview and Technical Details

Jstraw 09-06-2013 12:21 AM

I get a slight boost in engine performance using mid (89) but I see no difference between any of the premiums... I live in an area where we use 10% ethanol and have suspicions that our 87 is really 85 octane, but who knows?... I just notice the difference because I been fighting with my dealer about the mpg rating and my rig. I see the biggest difference in the winter which I always use mid grade due to the reformulation of fuel during the cool months, I tend to use the 87 in the summer and fall. My jeep liberty is very finicky and is how I learned our fuel isn't as advertised. I think our 89 is Actually 87, I live in a small town so no good fueling stations, only citgo and sheetz.

mjpjr45 09-06-2013 12:49 AM

Use regular. Using Premium or higher octane fuel is worthless and maybe harmful. The higher the octane rating the higher the fuel's resistance to burning. High octane is used in engines with higher compression or ignition timing set to use it. When using it in engines not setup for it, it will actually not burn as well or completely and cause higher emissions and possibly more build up in the engine. This can cause emissions system problems and possibly valve problems. Save yourself the trouble and the money, use what the owners manual recommends.

George Ross 09-06-2013 04:22 AM

In general, high octane fuel is only needed for high compression engines. Your owner's manual will lists the recommended fuel.

The 2013 manual says
"FUEL REQUIREMENTS
3.6L Engine
This engine is designed to meet all emissions regulations and provide excellent fuel
economy and performance when using high-quality unleaded “regular” gasoline
having an octane rating of 87. The use of premium gasoline is not recommended, as it will not provide any benefit over regular gasoline in these engines."

Dusthol 09-06-2013 06:39 AM

I run 91 non ethanol. If I run the 87 I get spark knock. I am also running a k&n filter which lets more air in.

RoadiJeff 09-06-2013 06:42 AM

Quote:

Originally Posted by Dusthol (Post 4337201)
I am also running a k&n filter which lets more air in.

In addition to more dust and dirt.

Shifty219 09-06-2013 07:57 AM

As others have said, run the octane specified in the manual. Using a higher octane than recommended is just throwing money away as it will not burn the fuel properly and leave more deposits on valves, cylinder walls and oil.
One thing you should do to help the longevity of your engine is to try and stay away from ethanol enriched fuels (e10). Ethanol is proving to be detrimental to engines not designed/equipped to run this additive. Ive heard its been harder to find stations not selling e10 but the Shells are usually your best bet

If you think running higher than specified octane gives you a boost in power, its usually just a placebo effect or you are in need of a tune up!

ahsumtoy 09-06-2013 08:20 AM

Filter and high octane
 
Quote:

Originally Posted by RoadiJeff (Post 4337233)
In addition to more dust and dirt.

If he is running a cold air intake, I can see where you get more dust but if it is just a replacement filter for the original and the box is closed, I don't see how it could get any more dust than the original.

Many years ago I had a boat with (2) 502 engines in it. The builders told me to run 87 Octane due to the compression of each engine. The builders of my engines said to run the lowest octane you can up until you hear knocking. These builders of my engines also ran top nitro boats and I trust them to know what they are talking about. They also told me I would get better power from a lower octane gas and the engine would run cooler than a higher octane gas. I tried using a higher octane one time and did not achieve better mileage and my top end was off by 4 mgh.

TOK 09-06-2013 08:22 AM

Quote:

Originally Posted by Dusthol (Post 4337201)
I run 91 non ethanol. If I run the 87 I get spark knock. I am also running a k&n filter which lets more air in.

I actually posted about this a week or so ago. Since putting on 35's, I was experiencing detonation just below 2000 RPM. Seemed like I was pretty much alone (as far as Pentastar owners go).

It was really hot out and I was running the air, so I'm not sure if it was a perfect storm of heat and load that caused it. I topped off with regular from another gas station to see if I just got crappy fuel. Haven't noticed pinging, but it also hasn't been as hot.

Plasticpirogue 09-06-2013 08:30 AM

Quote:

Originally Posted by Jstraw (Post 4333753)
I get a slight boost in engine performance using mid (89) but I see no difference between any of the premiums... I live in an area where we use 10% ethanol and have suspicions that our 87 is really 85 octane, but who knows?... I just notice the difference because I been fighting with my dealer about the mpg rating and my rig. I see the biggest difference in the winter which I always use mid grade due to the reformulation of fuel during the cool months, I tend to use the 87 in the summer and fall. My jeep liberty is very finicky and is how I learned our fuel isn't as advertised. I think our 89 is Actually 87, I live in a small town so no good fueling stations, only citgo and sheetz.

IF you "think our 89 is actually 87" then you need to contact your state office of weights and measures and file a complaint, because they are the ones who test and certify that the fuel at the pump meets the standards.

But here is a little secret....there is no such thing as mid-grade (89 octane) gasoline. Mid-grade is actually mixed at the pump; it's just a blend of regular unleaded and high octane unleaded...seriously. No 18 whee tanker is hauling around mid-grade; they only produce 2 grades of fuel for the retail automotive consumer.

ESP 09-06-2013 08:31 AM

Quote:

Originally Posted by George Ross (Post 4335441)
In general, high octane fuel is only needed for high compression engines. Your owner's manual will lists the recommended fuel.

The 2013 manual says
"FUEL REQUIREMENTS
3.6L Engine
This engine is designed to meet all emissions regulations and provide excellent fuel
economy and performance when using high-quality unleaded “regular” gasoline
having an octane rating of 87. The use of premium gasoline is not recommended, as it will not provide any benefit over regular gasoline in these engines."

This is all you need to go by, it states in your owners manual that your engine is designed to run it's best with 87 octane.

NFRs2000NYC 09-06-2013 08:39 AM

Quote:

Originally Posted by TomJeepWrang13 (Post 4333505)
Okay, so another question arose recently. My brother suggested I start using premium gasoline as opposed to regular unleaded for my new 2013 Jeep Wrangler Sport, because it'll be better for the engine and so forth. Now, I'm on a budget, and gasoline prices do not obviously care about whether or not people are a budget. So can someone please tell me if using Unleaded is okay for a new Jeep Wrangler. I've used nothing but unleaded in my old car which was a 4 cy. 2007 Toyota Yaris Sedan, which ran fine up until I traded it in. Thanks.

- Tom

No offense, but your brother doesn't know anything about cars...or gas for that matter. Premium gas isn't "better" for anything. It's not like regular has twigs in it, plus has sawdust, and premium is pure unicorn tears. It doesn't work that way. Unless your Jeep is tuned for super (93) use 87. If you live in a state that doesn't have 87 (like Colorado, where the regular is 85) run 89.

NFRs2000NYC 09-06-2013 08:40 AM

Quote:

Originally Posted by Jstraw (Post 4333753)
I get a slight boost in engine performance using mid (89) but I see no difference between any of the premiums... I live in an area where we use 10% ethanol and have suspicions that our 87 is really 85 octane, but who knows?... I just notice the difference because I been fighting with my dealer about the mpg rating and my rig. I see the biggest difference in the winter which I always use mid grade due to the reformulation of fuel during the cool months, I tend to use the 87 in the summer and fall. My jeep liberty is very finicky and is how I learned our fuel isn't as advertised. I think our 89 is Actually 87, I live in a small town so no good fueling stations, only citgo and sheetz.

I assure you, you are not getting a single ounce of performance by running 89 instead of 87. The only tiny performance gain you are getting is that your jeep weighs a bit less, since you have a lighter wallet. ;)

NFRs2000NYC 09-06-2013 08:41 AM

Quote:

Originally Posted by Dusthol (Post 4337201)
I run 91 non ethanol. If I run the 87 I get spark knock. I am also running a k&n filter which lets more air in.

If you are running the correct octane (87) and you get knock, you have much more serious problems. Running a higher octane is NOT a solution.

NFRs2000NYC 09-06-2013 08:45 AM

Quote:

Originally Posted by Shifty219 (Post 4338849)
As others have said, run the octane specified in the manual. Using a higher octane than recommended is just throwing money away as it will not burn the fuel properly and leave more deposits on valves, cylinder walls and oil.
One thing you should do to help the longevity of your engine is to try and stay away from ethanol enriched fuels (e10). Ethanol is proving to be detrimental to engines not designed/equipped to run this additive. Ive heard its been harder to find stations not selling e10 but the Shells are usually your best bet

If you think running higher than specified octane gives you a boost in power, its usually just a placebo effect or you are in need of a tune up!

This was the case a few years ago. Today, all manufacturers are mandated by law to design fuel systems that suffer no ill effects with a 10% ethanol addition. Mercedes even writes in their manuals that the fuel system is warrantied ONLY against 10% ethanol. Anything higher and they will not honor any fuel system warranty if there is any evidence of ethanol damage. From what I heard, they put that in writing just in case legislators tried to increase the ethanol content of gasoline, and now since passing a law of this nature would void millions of warranties, 10% is where we stand. It is now the norm, the manufacturers are building fuel systems to suffer no ills, so there is no need to worry.

Shifty219 09-06-2013 08:45 AM

I also forgot to add, with the use of e10 to standard fuel you could feel an effect in power difference. The read a lot from the guys who are crazy on logging fuel mileage and all have been showing a up to 3 mpg loss using e10 (ethanol enriched fuel)

NFRs2000NYC 09-06-2013 08:47 AM

Quote:

Originally Posted by Plasticpirogue (Post 4339625)
IF you "think our 89 is actually 87" then you need to contact your state office of weights and measures and file a complaint, because they are the ones who test and certify that the fuel at the pump meets the standards.

But here is a little secret....there is no such thing as mid-grade (89 octane) gasoline. Mid-grade is actually mixed at the pump; it's just a blend of regular unleaded and high octane unleaded...seriously. No 18 whee tanker is hauling around mid-grade; they only produce 2 grades of fuel for the retail automotive consumer.

I have a friend that owns a few gas stations on long island. 89 (midgrade) is a mixture of regular an super. If the proportioning valve that does the mixing is old, broken, etc, you can have a lower (or higher) octane rating that you paid for. It's rare, but it does happen.

NFRs2000NYC 09-06-2013 08:48 AM

Quote:

Originally Posted by Shifty219 (Post 4339977)
I also forgot to add, with the use of e10 to standard fuel you could feel an effect in power difference. The read a lot from the guys who are crazy on logging fuel mileage and all have been showing a up to 3 mpg loss using e10 (ethanol enriched fuel)

Meh, not really on a modern, stock, non-turbo vehicle. On a tuned sports car (say a Subaru STI or an Evo) you might notice a slightly...and I mean a marginal performance gain, but not on something like a Wrangler.

Plasticpirogue 09-06-2013 08:52 AM

Quote:

Originally Posted by NFRs2000NYC (Post 4340001)
I have a friend that owns a few gas stations on long island. 89 (midgrade) is a mixture of regular an super. If the proportioning valve that does the mixing is old, broken, etc, you can have a lower (or higher) octane rating that you paid for. It's rare, but it does happen.

Yup....try telling THAT to the average consumer. lol

Shifty219 09-06-2013 08:53 AM

Quote:

Originally Posted by NFRs2000NYC (Post 4339937)

This was the case a few years ago. Today, all manufacturers are mandated by law to design fuel systems that suffer no ill effects with a 10% ethanol addition. Mercedes even writes in their manuals that the fuel system is warrantied ONLY against 10% ethanol. Anything higher and they will not honor any fuel system warranty if there is any evidence of ethanol damage. From what I heard, they put that in writing just in case legislators tried to increase the ethanol content of gasoline, and now since passing a law of this nature would void millions of warranties, 10% is where we stand. It is now the norm, the manufacturers are building fuel systems to suffer no ills, so there is no need to worry.

The fuel systems are being upgraded to withstand the rot and corrosion the e10 introduces, but the engines are still the same components. I've seen the damage e10 has been causing to bike engines, now these are more "high strung" than what the average engine is in a car but the effects will still arise

Shifty219 09-06-2013 08:59 AM

Quote:

Originally Posted by NFRs2000NYC (Post 4340025)

Meh, not really on a modern, stock, non-turbo vehicle. On a tuned sports car (say a Subaru STI or an Evo) you might notice a slightly...and I mean a marginal performance gain, but not on something like a Wrangler.

This is from the f150 guys.. the pentastar is more advanced than the ol v8 tritons lol

LMT Rubi 09-06-2013 05:49 PM

Is there a reason why Arco AM/PM gas is usually cheaper than the other gas stations?

Xena1 09-06-2013 05:58 PM

The 3.6 motor has 10.2 compression ratio. Without computer controlled timing you would destroy the motor in one trip to the grocery store using 87 octane. The computer retards timing to compensate for the octane level. If you run a higher octane then the the timing is more advanced and hence more HP. I run 93 all the time not only because of the octane, but because it is the only grade available in NC with no ethanol. I find it worth the price difference.

xzy 09-06-2013 06:51 PM

Quote:

Originally Posted by Xena1 (Post 4352273)
The 3.6 motor has 10.2 compression ratio. Without computer controlled timing you would destroy the motor in one trip to the grocery store using 87 octane. The computer retards timing to compensate for the octane level. If you run a higher octane then the the timing is more advanced and hence more HP. I run 93 all the time not only because of the octane, but because it is the only grade available in NC with no ethanol. I find it worth the price difference.

That's very interesting. I've never read that before. Do you have a link that would explain it further ?

TOK 09-06-2013 08:11 PM

Quote:

Originally Posted by xzy (Post 4353753)
That's very interesting. I've never read that before. Do you have a link that would explain it further ?

I'd like to see dyno runs on 87 and 93 that show a difference. I figured the knock sensor retarded timing if it sensed detonation, but didn't increase power if it sensed a lack of it.


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