Performance/Gas milage?

[howard]

Can anyone give me an answer about getting better performance with premium gas over regular(87). I've been told that premium gets no better performance, but could give a little better mileage.

[TrojanDan]

Here are some threads:

This has been discussed many times I know!

Who has the best GAS on the market?

Pinging with 87 octane

Those are three threads that have this conversation. I think you'll find alot of good info there.

[SupraTitan]

Yes with out a doubt your truck will perform better with higher octane fuel. Higher octane fuel will allow the ignition system to give more timing, also avoid knock sensor intervention. In closed loop operation it allow for a leaner mixture the list goes on and on. Another consideration is with most 4 valve aluminium pent roof heads, such as the head on the VK56 they get hot. Its proven that higher octane fuel lowers head temps, this in turn lowers cylinder temps and wards off detonation. Also lowers oil temps in the head which otherwise could lead to oil sludging.

My recommendation with the titan would be for everyday commuting if you do not experience pinging than run 87. When towing or when you plan on giving the engine a workout spend the extra loot on the good stuff, your engine will thank you in time.

[todd92]

If the owners manual says 87, the ECU is calibrated to give max ignition advance for 87. To get more ignition advance would require an aftermarket 'chip', calibrated for higher octane. Aluminum heads don't 'run hot'. Higher octane doesn't 'burn cooler'. If you are worried about 'oil sludging', use a synthetic, they don't 'sludge'. I'm surprised that some people say thier trucks are pinging on 87, mine doesn't ping at all.

[SupraTitan]

Originally Posted by todd92

If the owners manual says 87, the ECU is calibrated to give max ignition advance for 87. To get more ignition advance would require an aftermarket 'chip', calibrated for higher octane. Aluminum heads don't 'run hot'. Higher octane doesn't 'burn cooler'. If you are worried about 'oil sludging', use a synthetic, they don't 'sludge'. I'm surprised that some people say thier trucks are pinging on 87, mine doesn't ping at all.

First off you better freakin believe that the 4 valve pent roof head runs hot, it does so by design, and is able to run much hotter than other designs without causing detonation. How the heck do you think they get the output that they do. Next, higher octane doesn't necessarily burn cooler but what it does do is ignite when its supposed to affording a more effiecient burn hence less wasted energy and less heat. All you need is an EGT(exhaust gas temp) guage to witness this phenomena. Also this is a Nissan not a Dodge, it doesn't need a cheesy chip to take advantage of something as simple as higher octane fuel. Sportcompact car mag found substantial horsepower gains with a stock nissan 350Z running 100 octane unleaded vs. the nissan recommended min 91. I had been running sunoco 100 octane unleaded in my supra, shortly after the clutch started slipping in third gear, went back to 93 pump about 100 hundred miles of abuse at the same boost level and no more clutch slipping, figured what the hay and threw in some V.P. red at about a 50/50 mixture and whamo mucho clutch slip in 3rd gear. This is a 15 year old ecu that obviously makes more power with higher octane. I know using a turbo car as an example is showing the extreme but the same principals apply. A stock titan will see minimal gains but the gains will increase when exhuast mods and intake mods find there way onto the truck. There are also much better solutions to a chip, such as installing an apexi super air flow computer and dyno tuning with a wide band o2 sensor. Bigger gains, safer operation and not that much more expensive.

[todd92]

You are using leaded race gas in your Supra (VP Red). Good for you. I hope it's a track car, because you just wasted your catalytic converters. Not sure there is much to prove or disprove by your slipping clutch dyno. The 350Z is designed to run on 91. The ECU may designed to take advantage of higher octane (probably up to 93). I doubt this is the case with the Titan, but I could be wrong. The heads are designed to allow for a higher compression ratio without raising the octane requirement. If this is what you mean by running hot, perhaps, but what you really meant is the head design is more efficient. Use premium all you want. You not hurting anything but your wallet.

[rvandam]

If your truck runs well on 87, and therefore the computer does not need to influence timing, you are better off running 87 for efficiency. Not only is 87 cheaper, but it also contains more energy per gallon than higher octane gas.

Now, as far as performance, I leave that to the experts.

[Zardoz]

Originally Posted by todd92

If the owners manual says 87, the ECU is calibrated to give max ignition advance for 87. To get more ignition advance would require an aftermarket 'chip', calibrated for higher octane. Aluminum heads don't 'run hot'. Higher octane doesn't 'burn cooler'. If you are worried about 'oil sludging', use a synthetic, they don't 'sludge'. I'm surprised that some people say thier trucks are pinging on 87, mine doesn't ping at all.

Some cars are designed like this, Nissan does not. The ECU advances timing
in response to the knock sensor along with other things. You will get slightly
more power and MPG with higher grade fuel but it is not a cost effective
situation. Nissan has always had pretty neat knock sensors and ECU systems
with regards to fuel quality. I use to get about 1 MPG better on my 95
VG30 hardbody when using premium vs regular.

Zardoz

[Austin]

Have any of you guys actually done testing on a 5.6L Titan motor?





*cricket*




*cricket*

Plug a quality laptop based obd2 scanner into the truck. You can get quite an amazing amount of information... Like seeing that the ecu runs over 35-40 degrees of timing advance in places at WOT, on 87 octane fuel.

You don't want any more timing advance, and the ECU wouldn't give it to you even with higher octane. This is not a turbo car. It's an NA engine, with an ECU designed for an NA engine. Not nearly as adaptive as any turbo ECU because it doesn't need to be. NA applications run into far fewer variables and don't need to be as adaptive.

Higher octane fuel doesn't burn as easily. That is good if you're pushing things - like running 10 or 20 psi of boost.

The ONLY reason to use higher than 87 octane is if you experience pinging/spark knock with 87 octane. If the truck runs good on 87 octane and you put 91 octane in it, at the very least you're emptying your wallet faster than you need to.

[Steve04SE]

Originally Posted by Zardoz

Some cars are designed like this, Nissan does not. The ECU advances timing in response to the knock sensor along with other things. You will get slightly more power and MPG with higher grade fuel but it is not a cost effective situation. Nissan has always had pretty neat knock sensors and ECU systems with regards to fuel quality. I use to get about 1 MPG better on my 95 VG30 hardbody when using premium vs regular.

Zardoz

Can you please reference your source for this comment?

[juma]

I'm not sure if the titan has fuel maps for different octanes but if it doesn't, the premium gas won't have time to burn completely and will leave deposits. I'm gonna wait till the computer guys break down the code and tell us before I use premium.

juma

[Half Shovel]

I just have to get my .02 in here....

You won't get a cost effective increase in performance or gas mileage with higher octane gas in your Titan. It won't help towing, it won't boost acceleration, it won't do ANYTHING.

...well, ok, it might do ONE thing...turn your Titan into an Octane Junkie, by leaving carbon deposits (a result of cooler combustion, I believe) in the cylinders, making "hot spots" that tend to increase the chances for detonation. After a good accumulation of these deposits, you'll have to run premium fuel just to prevent the detonation caused by the build-up.

Folks, don't waste your money.

HS

[Big Platinum]

I can smell the testosterone cooking!!!!!!!!!!!!!!!

I love it!!!!!!!!!!!!!!111

[avroflyer]

All I know is that 87 works great in my Titan, my Frontier SC took 93, the Frontier got worse gas mileage that the Titan, I am very happy! A 93 octane vehicle???? NEVER AGAIN! Its expensive!

Jim

[sleightofhand]

87 octane is all you need. There is no performance to be gained with higher octane gas. If you do have a ping running 87 you need to get your computer checked, or you need a tune up. http://www.state.mn.us/cgi-bin/porta...gency=Commerce