Premium VS Regular Gas

[TheDave]

Mike, I agree that you should try to use higher octane when you have the option in our higher compression motors. The OP was concerned because of shortages, not because of cost.

 

[CaptainSpalding]

I used to own a 1985 Mercedes G-Wagen. It had an interesting feature. Under the hood there was a little plastic cap. If you unscrewed it, pulled it off, and looked inside it, there were a couple of resistors. It screwed into a base in which there were a couple of detents, allowing the cap to be positioned in one of two orientations. The idea of it was that if you had to fill up with gas that was of the improper octane, or had been stored a long time, or just generally suspect, you would unscrew the cap, rotate it a few degrees to the other detent and screw it back down. This essentially detuned the engine to accommodate the poor quality fuel.

 

[I busted]

Hi All,

Get this, We live in the Chicago land area and purchased a new 2012 LR4 a few months ago. During our walk through of the vehicle, the sales per stated that on the recommendation of the land rover technician we should use middle grade gas (silver) 89+ octane due to the height levels of ethanol used in the Midwest. Anyone know if there is any truth to this? I can't see any reason that he would tell us that after we already purchased the vehicle if it wasn't true.

Any info would be greatly appreciated.

Thanks,

JC

 

[Land Rover Joe]

All,

Great topic and really relevant to the community!

JC,

In the age of exorbitant gas prices and cheap additives and fuel alternatives, fuel quality and composition is a real problem. I am a bit extreme and live/work in Africa, so I bought a fuel test kit (search for “fueltestkit”) to see what exactly was floating around in my fuel. In my case: pure gasoline. I have never found water or contaminants in gasoline at a reputable pump in Africa-yet. For the Africa-philes, almost all trucks here are diesel, which has a lot of advantages. But I have a couple of die-hard friends who swear that gasoline is better because the quality control and shipping of the fuel is much better (hence safer and more consistent). So far…they have been right. Diesel has a lot of contaminants out here.

But back to the subject relevant to you: many folks in the states are now “blending” fuels and then selling them—cost savings to them, of course, with the risk to your engine. State laws vary, but you will NOT know what the blend is when you pull up to the pump. So…you could be fueling up with 15% ethanol stateside (hasn’t been a problem for me in Africa yet). This is a real problem, especially for a high performance engine which was specifically designed for a specific grade and quality of fuel. I recommend checking the internet and learning more about it…you may be very surprised what you find.

For the group:

DisoMike is right—just buy the higher quality gas for your LR4 babies. In Africa, I have no option, so I buy straight 86-87 Octane (French made fuel by Total). While the fuel is clean and pure, it is NOT the right grade for this vehicle. I have very low mileage and have numerous problems with lower grade gasoline.

First: Mike said it best-you will suffer severe losses in power and fuel economy. If you though the engine was a gas guzzler before…see what you get with low-grade gasoline (and with a lot less torque)! I can’t speak about the injectors; but even worse, the poor burn rates will screw up your O2 sensors and may ruin your catalytic converter. After the first two years of running the truck, the check engine light came on. My Innova OBD2 reader kicked code P2098 “Post Catalyst Fuel Trim System Too Lean Bank 2.” I tried everything to figure out was causing the code, too include finally pulling out (all four) the 02 sensors. Sure enough, they were completely coated with carbon residue (and thus did not work). I had bought a replacement 02 sensor from Atlantic British, but they sent me the wrong part number…and wouldn’t replace it. So—I will rewire the thing (it just has a different plug) when I get a chance with one of the old sensors. Anyway, I cleaned all the sensors with Carbonator cleaner and re-installed. Code went away. Hopefully I will never have to do a vehicle emissions test…

My conclusion: the poor fuel quality, combined with relatively short drives and low engine speed for me in Africa, caused incomplete burns in the engine which kicked all the soot out into the exhaust. Over time, that causes problems on OBD2 and beyond vehicles like the LR4. I also have a contract with Polaris Labs to test my engine oil and coolant (just to be safe), and haven’t reported any problems with either those fluids. In fact, I run the engine with Royal Purple and got almost 18 months out of the engine oil (very low mileage but extreme conditions). So, fuel quality shouldn’t have much effect on engine oil performance.

But, you absolutely CAN drive the vehicle with “normal” gas, so don’t worry about it in a pinch. Just use the best gasoline you can buy at the pump.

Hope that helps and curious if anyone has any similar experiences or comments!

Land Rover Joe