QX56 vs. Titan - Page 2

pciley · 10-07-2004, 09:51 PM

I wouldn't be surprised if the computer's fuel maps are very similiar for both vehicles.
Remember the Nissan Tech article released at about the same time as the Titan (no, I can't find it, so don't ask me to scan it... )? It was explaining how Nissan wanted to bring a truck to market that could be compared to the domestics, and they felt that introducing a gas-guzzling pickup that required premium fuel would not be very well accepted .. I am totally paraphrasing an article I read 6 mos ago so please correct any inconsistencies...

Anyways, when you run premium in the Titan, the timing does advance. See Juma's thread:
testing timing advance
So you will see a power gain. I got better times at the track with premium fuel, it was a minor difference, but it is there.
Maybe if the Titan REQUIRED premium fuel it would also be 315 hp??

As stated, the numbers are under rated. I like that. Its modest. You can roast any other stock production pickup other than the lightning, srt-10, and sc'd harley davidson f150s. That's saying alot. Its a proven hemi-eater either way.

virus · 10-08-2004, 05:26 PM

Like many have said, premium fuel will NOT improve performance in a vehicle that has compression ratios below 10.5-11. It's simply a waste of money. 87 octane has the same amount of detergents as the 93 does as required by law. 87 octane actually has more potential power than does 93 because it burns much faster. Higher octane and power is a common thought. However, if your car requires premium and you use 87, the engine can lose as much as 8-10hp. Maximas require premium fuel and you can definately tell the butt dyno difference. If you use 87 in a Maxima, the computer will retard your timing to compensate for the lower octane fuel. Since 93 octane burns much hotter than 87, you could actually cause damage to the cylinders if you continue to use premium fuel in the Titan. If the Titan says 87, use 87.

juma · 10-08-2004, 07:27 PM

I vote for pciley. juma

Titan Power · 10-09-2004, 12:24 AM

Quote:

Like many have said, premium fuel will NOT improve performance in a vehicle that has compression ratios below 10.5-11. It's simply a waste of money. 87 octane has the same amount of detergents as the 93 does as required by law. 87 octane actually has more potential power than does 93 because it burns much faster. Higher octane and power is a common thought. However, if your car requires premium and you use 87, the engine can lose as much as 8-10hp. Maximas require premium fuel and you can definately tell the butt dyno difference. If you use 87 in a Maxima, the computer will retard your timing to compensate for the lower octane fuel. Since 93 octane burns much hotter than 87, you could actually cause damage to the cylinders if you continue to use premium fuel in the Titan. If the Titan says 87, use 87.

Sorry, you have most of your "facts" bass-akwards. This is silly how many octane debates there are on this list between the few who know what they are talking about, the the rest that choose to spread mis-information.

First, where did you come up with this arbitrary 10.5:1-11.0:1 (which is quite a spread) rule? There are many aspects of engine design that influence knock propensidy, compression ratio is just one of them.

Second, you correctly state that 87 octane has more energy content and burns faster. But because it is fast burning it is more prone to pre-ignition. Then you contridicted yourself and said 93 burns much hotter... after you said 87 has more power potential and burns faster.

The icing on the cake was when you wrote that running 93 octane "could actually cause damage to the cylinders." Do you have any clue what you are talking about? Which part of "the cylinders" are in harms way? The walls?

While I belive that there is an advantage to using premium fuel over 87 in our trucks, for me it is not enough of a difference to justify the added expense on a daily basis. It is not easy to feel the difference between 305 and 315hp in a 5000lb. truck. But there is a difference, and you certainly will not hurt your truck using premium fuel. The other myth of "once you switch, you can't go back" is also unfounded b.s. When switching either way, you need to allow time for the ECU to re-adjust. Or reset it and speed up the process.

Jason K.

P-Kidd · 10-09-2004, 04:23 AM

Quote:

Originally Posted by mininsx

Be carefull if you've only been using premium...

I read somewhere a long time ago, that if you run more than 3 tanks of premium through your engine your stuck with using premium. If you switch back you'll have issues...

Not sure how true it is, but might be worth doing some homework on before you switch back to regular...

I read the same thing a while back.... My wife's 99 Pathfinder is a perfect exampe of this.

webslinger1977 · 10-14-2004, 08:21 AM

The infinity has a higher compression ratio than the the titan look on msn.com autos they state displacement and compression there.

JMC · 10-14-2004, 10:43 AM

http://www.carseverything.com/content/article/1497.3 From what I have seen ALL the endurance engines show to be 9:8.1

JS02 · 10-14-2004, 11:21 AM

I agree with JMC. All the info that I have seen shows the QX56 and the Titan to have 9.8 compression ratio. I used 87 octane for 20K miles and I had no problem with it. I ran one tank of premium and I could not tell much difference. I now have driven over 4K miles with 91 octane and over that many miles I have found it does seem to have more power. I also have kept close records of fuel economy and I have seen about 7% increase in fuel economy. Where I live it is about a trade off with the extra 10 cents a gallon and the extra MPG.

Mike H. · 10-14-2004, 11:56 AM

Quote:

Originally Posted by JS02

I agree with JMC. All the info that I have seen shows the QX56 and the Titan to have 9.8 compression ratio. I used 87 octane for 20K miles and I had no problem with it. I ran one tank of premium and I could not tell much difference. I now have driven over 4K miles with 91 octane and over that many miles I have found it does seem to have more power. I also have kept close records of fuel economy and I have seen about 7% increase in fuel economy. Where I live it is about a trade off with the extra 10 cents a gallon and the extra MPG.

Ditto .

smoothTitan · 10-14-2004, 12:47 PM

I BUY PREMIUM FUEL BECAUSE IT GIVES ME MORE MPG , and it smeels better,and taste better.

IQ9 · 10-14-2004, 01:56 PM

Yeah smell and taste

Titan Power · 10-15-2004, 12:12 AM

Quote:

Yeah smell and taste

Actually, 110+ octane leaded race gas does smell good.

Jason K.

crelai · 10-15-2004, 01:52 AM

Probably the QX65 has a different timing curve. But the QX65 is also heavier than the Titan which probably negates the torque and horsepower.

General rule of thumb for Octane is to run as low as possible without "knocking". I've done 87 so far without a problem.

JS02 · 10-15-2004, 06:54 AM

Tests with the QX56 have shown that it has more power than the Titan. It is heavier and has still run very impressive times. It's 4X4 times are as good or better than the Titan's best 4X2 times even with the added weight penalty of about 300 pounds. The QX56 has run 0-60 times of 6.8 and low 15 second quarter mile times. Unless this was a "special" QX56 it would seem that it is making more power.