Sentences with phrase «low octane»

I would suggest that the OP's modern 10.5:1 CR engine can cope with lower octane fuel because of advances in combustion chamber design.

High compression engines (performance cars) would cause low octane gas to combust under the pressure alone rather than from the spark plug firing, resulting in knocking, which is very bad for the engine.

Currently, ethanol is blended into a gasoline blendstock formulated with lower octane rating... Read more →

The effective compression ratio is about 8:1, very low, so the justification for not using low octane fuel is incorrect.

Purchasing 91 octane fuel (where offered) simply means that more fuel of higher octane is blended with commensurately less fuel of lower octane, than when purchasing a lower grade.

Some can tolerate lower octane numbers for long periods by retarding engine timing or reducing turbocharger boost.

My view is: Try lower octane gas, if you notice either knocking or decreased performance then you should stick with the higher octane fuel.

The rattle / knocking noise when using too low octane fuel, incorrect timing or bad tuning etc is called «knock» also known as detonation and this is where the fuel / air mixture is ignited when it isn't supposed to / at a different time to when the spark plug is fired.

Conversely, some higher compression engines can downtune in order to cope with low octane petrol... some can't.

Here's an excerpt from my eating guide (The Body Fuel System), the chapter called «High and Low Octane Beverages and How to Use Them» — just to give you a few of the facts I've learned about alcohol and how it affects (in this case) our weight and fitness goals.

As far as I know premium fuel is (or was) better suited for engines with higher compression ratios (10:1 or more), since lower octane fuel is more likely to combust before the sparkplug fires.

One owner's manual might specify premium fuel with no exceptions except in emergencies (Subaru WRX), while another owner's manual states lower octane merely reduces power with no long term harm (Nissan Maxima).

Modern day engines are equipped with knock sensors which will prevent any adverse effects from the slightly lower octane fuel.

Probably the most common cause of that is a head gasket with a leak between the two, which could be caused by high compression / detonation (there are several possible causes for that including incorrect ignition timing, low octane gasoline), an engine overheat, uneven head bolt torques and / or a defective head gasket.

The car is built for markets lacking E85 biofuel, optimised for running on low octane fuel.

Only in extreme cases such as very high compression ratios, very low octane fuel or too much ignition advance can it benefit a normally aspirated engine.

To its credit, the Mondeo can take low octane 91RON petrol (while it's still available) and has a creamy - smooth power delivery.

Higher octane fuel can withstand that pressure, whereas lower octane fuel will ignite all at once and melt the engine.

Try lower octane gas, if you notice either knocking or decreased performance then you should stick with the higher octane fuel.

«Premium» grade is fuel of higher octane, and the minimum grade sold is fuel of lower octane.

If you're running low octane fuel and push the car hard enough, its conceivable that long term damage can still be done.

Pre-ignition can be caused by too much spark advance or too low octane gas.

If used on the street with lower octane fuel, 93 octane rating or less, drivability issues may be experienced.

High performance cars like the BMW M3 and the Audi S4 required 91 octane, and the engine management system was so calibrated toward high performance that running lower octane fuel was detrimental to the engine's health.

This can be especially helpful with ethanol - gas mixes and lower octane fuels.

An analogy can be drawn between running a car on bad gas with low octane and containing water, dirt and other impurities and our consuming a low quality diet.

Use the lowest octane your car needs.

Can you explain how running a lower octane in the absents of spark knock causes head gasket damage?

Some cars can tolerate a lower octane for an unspecified time by retarding timing.

As higher temperature boost is added, low octane gas will become problematic quickly.

Too add on I have a premium only car also, and when you put regular gas in the knock sensors pick it up so the ecu can retard or advance timing to compensate for the knock that lower octane fuel gives.

If you fill up with low octane fuel, don't race around like an idiot and you should be fine.

However, the Prius has a pretty high compression ratio (13:1), so it will be more sensitive to low octane fuel than if it were around 11:1 or even 12:1.

Using a lower octane fuel than recommended can result in the fuel / air mixture self - igniting (commonly called «knocking»).

87 is mainly the lowest octane available (some higher elevations get 85 octane).

Was told due to low octane gas, this can happen and it happens often.

Most fuel filling stations have two storage tanks (even those offering 3 or 4 octane levels): those motorists who purchase intermediate grade fuels are given a mixture of higher and lower octane fuels.

If the fuel you got was of a lower octane rating than that demanded by the engine's compression ratio and spark advance detonation could result and cause the types of failures previously discussed.

In particular, it is possible that detonation, or spark knock, may occur in hot climates or hot running conditions with fuel that has a lower octane rating than 100.

The actual difference would be a bit smaller, since you usually get a little better MPG with the higher octane (or so they claim), or even in favor of the 91 if the lower octane fuel causes a costly repair (multiply cost of repair by the probability of repair)

(*) Diesel fuel is not used in a gasoline engine, so its low octane rating is not an issue; the relevant metric for diesel engines is the cetane number

A water - injection system was added to prevent detonation (knocking) from the low octane 80's gasoline.