Fuel type?

I am assuming that this beast will use regular gas. Does anyone know for sure? I find it interesting that toyota tacoma's v6 uses premium and it's a 4.0 liter but with HP and torque similar to the ridgeline.

Both the Pilot and Odyessy use regular, although Honda recommends premium when towing above 3500 lbs. The Ridgline is using an engine that is based on the Pilot/Odyessy.

On a side note, the Acura MDX is using a similar engine and requires premium but it producing 265HP & 253 ft lbs. A little higher the the Ridgeline

My Odyssey does not require premium fuel. However, oddly, it is rated at 205HP on regular unleaded and 210HP on Premium. During hurricane season I had to run a couple of tanks on regular and the performance wasn't as "crisp". However, I don't know that you can really feel a 5 HP difference. Nonetheless, that could explain why Acura is recommending Premium - so they can claim higher horsepower in the luxury line over the regular Honda.

I run regular unleaded in my '05 Odyssey Touring and it has plenty of get up and go. I believe that the engine in the Ridgeline is the same engine as the Odyssey (minus the VCM). I am assuming that you should only need regular gas for daily driving. The website, as far as I have been able to find, does not mention needing premium fuel (nor does it say that all you need is regular either).

That there would be a recommended difference ("...premium for towing...") is interesting. I had always thought that the octane rating pertained solely to engine compression (retards premature detonation) and that the computer would change the mix anyway depending on how hard you stomp on the gas so there shouldn't be a need...I've heard engine age can affect compression but can the load do the same? Can using premium (in a regular engine) really give better gas mileage or more power?

Probally premium...

If I remember right the manual recommends an octane rating of 86 or better, and I think your typical regular gas (Chevron, Texaco, etc) is 87. That's what I've been putting in and am plenty pleased with the performance and fuel economy (21.5 w/ just over 2000 miles, I can't complain). I do hardly any towing right now so I can't speak to that, but in general driving for most vehicles premium gas is a waste of $.

Has anyone tried ethanol? Can the Ridgeline run with Ethanol?

Going on 14 months with the RL and nothing used but 87 octane. Works for me.

Has anyone tried ethanol? Can the Ridgeline run with Ethanol?

The Ridgeline can run on fuel with up to 10% ethanol content.

E-85 FlexFuel is NOT approved for use in your Ridgeline. You'll have to wait for the 2008 engine upgrade for FlexFuel.

Using high-octane fuel should not produce more horsepower or mpg. However, under heavy loads (which means higher internal cylinder pressures), a higher octane fuel will reduce the possibility of premature detonation of the fuel-air combimation. Heavy loads, in this case, could mean "while towing" or if you like to "gun it" from a stop.

The higher-power myth usually stems from the fact that higher-powered cars usually have very high compression ratios and, therefore, require higher octane fuel to prevent damage to the engine.

Octane myths:
http://www.state.mn.us/mn/externalDocs/Commerce/Gasoline_Octane_Facts_102902052227_OctaneFacts.pdf

-brian

Using high-octane fuel should not produce more horsepower or mpg. However, under heavy loads (which means higher internal cylinder pressures), a higher octane fuel will reduce the possibility of premature detonation of the fuel-air combimation. Heavy loads, in this case, could mean "while towing" or if you like to "gun it" from a stop.

The higher-power myth usually stems from the fact that higher-powered cars usually have very high compression ratios and, therefore, require higher octane fuel to prevent damage to the engine.

Octane myths:
http://www.state.mn.us/mn/externalDocs/Commerce/Gasoline_Octane_Facts_102902052227_OctaneFacts.pdf

-brian

Yes, and no.

Let's go thru this step by step.

First, if EVERYTHING is equal you will get LESS power out of 93 octane fuel than you would with 87 octane. How can this be? 93 octane fuel has fewer BTU's per gallon than 87 octane.

IF the engine ECU is not adaptive and able to compensate for higher octane fuels there is absolutely no benefit to using higher octane fuels. There's actually several penalties for using higher octane fuels, they include higher initial cost, lower fuel mileage, lower power.

Yes, the above is contrary to popular opinion. The truth is often contrary to popular opinion.

Now, let's look at the other side of the coin. The Ridgeline has an adaptive ECU. There is no sensor that knows what octane fuel you pumped into the engine, but we do have a several other sensors that let the engine adapt to the quality of the fuel.

We'll just use the knock sensor (sometimes called a detonation sensor). This sensor lets the ECU know when the fuel is detonating. Now there are several reasons fuel could be detonating, but the most common reason is that the ignition timing is too far advanced for the quality of fuel being used.

The Ridgeline ECU has the ability to both advance and retard timing as needed. Under extreme load conditions such as full throttle acceleration and towing the ECU attempts to advance the ignition timing to get more power out of the engine.

The ECU can only work within preset limits, but let's say you're towing a 5000 pound trailer and need heavy acceleration to enter the highway. Let's examine two scenarios (I'm going to use arbitrary and exagerated advance numbers for the examples):

87 octane fuel: We have 100% on the throttle position sensor and are at 4000 RPM's. The ECU base map says to use 20 degrees of ignition advance. No detonation is determined. The ECU attempts to advance the ignition timing to 22 degrees BTDC... OK, then tries to advance more to say 24 degrees, but OOPS the knock sensor reports back that we've got some detonation. The ECU then drops the timing back to 22 degrees to prevent detonation damage.

93 octane fuel: We have 100% on the throttle position sensor and are at 4000 RPM's. The ECU base map says to use 20 degrees of ignition advance. No detonation is determined. The ECU attempts to advance the ignition timing to 22 degrees BTDC... OK, then tries to advance more to say 24 degrees and everything still OK, the ECU continues this pattern and finally gets some detonation at 30 degrees so it backs off to 28 degrees.

So under the same loads, RPM's, etc. we were able to get 28 degrees of ignition advance with 93 octane, but only 22 degrees with 87 octane. The engine will produce more power with the 93 octane fuel under extreme load conditions.

To present another viewpoint quickly ... if you're driving on the highway at 70MPH, not towing, etc. (normal driving) you will not receive any benefit from using the higher octane fuel (just the opposite really). The benefits only come into play during near 100% load conditions.

Hope this helps!

simply put,


some folks enjoy subsidizing the poor souls at OPEC running high octane when not needed.

As stated ad nauseum...the RL owners manual says use high octane when towing. otherwise use regular unleaded.

simply put,


some folks enjoy subsidizing the poor souls at OPEC running high octane when not needed.

As stated ad nauseum...the RL owners manual says use high octane when towing. otherwise use regular unleaded.

With all due respect, the 07 manuals don't say to use premium. In fact, if the motor has an adaptive ECU as mentioned above, there is little point.

If I missed something in the manual please let me know.

Here's what the Owner's Manual says:

Fuel Recommendation

Your vehicle is designed to operate
on unleaded gasoline with a pump
octane number of 87 or higher. Use
of a lower octane gasoline can cause
a persistent, heavy metallic rapping
noise that can lead to engine damage.
We recommended using a quality
gasoline containing detergent
additives that help prevent fuel
system and engine deposits.
In addition, in order to maintain good
performance, fuel economy, and
emissions control, we strongly
recommend, in areas where it is
available, the use of gasoline that
does NOT contain manganese-based
fuel additives such as MMT.
Use of gasoline with these additives
may adversely affect performance,
and cause the malfunction indicator
lamp on your instrument panel to
come on. If this happens, contact
your authorized dealer for service.
Some gasoline today is blended with
oxygenates such as ethanol or
MTBE. Your vehicle is designed to
operate on oxygenated gasoline
containing up to 10 % ethanol by
volume and up to 15 %MTBE by
volume. Do not use gasoline
containing methanol.
If you notice any undesirable
operating symptoms, try another
service station or switch to another
brand of gasoline.
Premium fuel is recommended when
towing in certain conditions (see
page 224).
For further important fuel-related
information, please refer to your
Quick Start Guide.

Follow up from Owner's Manual page 224 as referenced above:

Towing performance can be
affected by high altitude, high
temperature, or when climbing
steep grades. Therefore, premium
fuel (premium unleaded gasoline
with pump octane number of 91 or
higher) is recommended when
towing more than 3,500 lbs (1,590
kg).

Using high-octane fuel should not produce more horsepower or mpg. However, under heavy loads (which means higher internal cylinder pressures), a higher octane fuel will reduce the possibility of premature detonation of the fuel-air combination. Heavy loads, in this case, could mean "while towing" or if you like to "gun it" from a stop.

The higher-power myth usually stems from the fact that higher-powered cars usually have very high compression ratios and, therefore, require higher octane fuel to prevent damage to the engine.

Octane myths:
http://www.state.mn.us/mn/externalDocs/Commerce/Gasoline_Octane_Facts_102902052227_OctaneFacts.pdf

-brian
Your Right on, it always amazes me how people misunderstand octane. In layman's terms octane is the resistance of fuel to burn. This means that higher octane burns slower and puts out less energy. The difference is it produces a more controlled burn less susceptible to detonation. Detonation can cause damage to valves and pistons in your engine. It would only be recommended to use such a gas when engine is under a load or knocks and pings. Actually if your engine knocks and pings it detects this and retards you timing to accommodate this situation which might lower your gas mileage, but in absent of these conditions it not helping you at all. Do what you want but in my opinion your just throwing your money out the window.