mts Posted August 17, 2008 Report Share Posted August 17, 2008 Many people use premium gasoline thinking that it’s better for engines than regular. That can be a costly misconception. Regular gas typically has an octane rating of 87, while premium is rated at 91 to 93. But octane grades don't represent "good, better, best"; they simply measure a fuel's resistance to pre-ignition (pinging or knocking), a condition in which gasoline burns uncontrollably in the engine’s combustion chambers, possibly leading to engine damage. The higher the octane rating, the more resistance it provides. Most engines are designed to run fine on regular gas. Using premium in them doesn’t improve performance; it only costs more money. Even many cars for which premium is recommended can use regular gas without a problem. That’s because most modern engines can detect the presence of pre-ignition (which usually occurs under high-load conditions) and automatically make adjustments to eliminate it. The tradeoff when that happens is a slight decrease in power and gas mileage, but most people probably won’t notice it. Generally, if your owner’s manual says "premium recommended," you can safely use regular gas. Some engines do require premium gas. They’re typically more powerful ones used in sports and luxury cars. Those engines use a higher compression ratio, which can make them run hotter and make them more vulnerable to pinging. The high octane fuel helps them resist the condition. 10:1 IS NOT HIGH COMPRESSION.... Quote Link to comment Share on other sites More sharing options...
latinopikachu Posted August 17, 2008 Report Share Posted August 17, 2008 apparently the millenia was more like a black project and only referred to as the ZX on a need to know basis. :clapping: yesterday i was cruising along when i saw a decidedly evil shape lurking in the background, for some reason i didnt immediately recognise it, but it was a dark green 95 S, it suddenly accelerated and went around me and i gave chase, what a glorious sight that must have been to watch Quote Link to comment Share on other sites More sharing options...
enginph Posted August 17, 2008 Author Report Share Posted August 17, 2008 Many people use premium gasoline thinking that it's better for engines than regular. That can be a costly misconception. Regular gas typically has an octane rating of 87, while premium is rated at 91 to 93. But octane grades don't represent "good, better, best"; they simply measure a fuel's resistance to pre-ignition (pinging or knocking), a condition in which gasoline burns uncontrollably in the engine's combustion chambers, possibly leading to engine damage. The higher the octane rating, the more resistance it provides. Most engines are designed to run fine on regular gas. Using premium in them doesn't improve performance; it only costs more money. Even many cars for which premium is recommended can use regular gas without a problem. That's because most modern engines can detect the presence of pre-ignition (which usually occurs under high-load conditions) and automatically make adjustments to eliminate it. The tradeoff when that happens is a slight decrease in power and gas mileage, but most people probably won't notice it. Generally, if your owner's manual says "premium recommended," you can safely use regular gas. Some engines do require premium gas. They're typically more powerful ones used in sports and luxury cars. Those engines use a higher compression ratio, which can make them run hotter and make them more vulnerable to pinging. The high octane fuel helps them resist the condition. 10:1 IS NOT HIGH COMPRESSION.... Miller compression ratio is even 8:1 Quote Link to comment Share on other sites More sharing options...
///BHRpowered Posted August 17, 2008 Report Share Posted August 17, 2008 "measure a fuel's resistance to pre-ignition (pinging or knocking), a condition in which gasoline burns uncontrollably in the engine's combustion chambers, possibly leading to engine damage. The higher the octane rating, the more resistance it provides." umm yesh, and in a boosted engine, and in modern engines where things are very precisly controlled it makes a huge difference, you think that power lose is because there isn't as much energy in the fuel, wrong. if it were another car I wouldn't care that your all ruining them, but these are millenia's and we all need to do our part to keep them around Quote Link to comment Share on other sites More sharing options...
///BHRpowered Posted August 17, 2008 Report Share Posted August 17, 2008 saint - the millenia'c compression is 10, no idea where your getting 8 from, maybe the fumes from cheap gas building up carbon in the brain? http://www.kbb.com/KBB/UsedCars/Specificat...p;Mileage=50000 Quote Link to comment Share on other sites More sharing options...
latinopikachu Posted August 17, 2008 Report Share Posted August 17, 2008 avon, i say, avon Quote Link to comment Share on other sites More sharing options...
enginph Posted August 17, 2008 Author Report Share Posted August 17, 2008 That compression ratio is no longer a good definition for MCE. The effective ratio (from intake valves closed to TDC) is 8:1 which is more important when it comes to octane. Read about MCE or you better read the new avon catalog. http://eunos.com.au/data/800/mazdafiles/index.htm At first glance the compression ratio would appear to be 10:1 (swept volume compared to clearance volume), however, for the first 20 percent of the compression stroke, the intake valves remain open. Since the actual compression stroke does not begin until the valve closes, the compression ratio is "artificially" reduced down to 8:1. mc_graph4 Intake valve duration is from two degrees before TDC until 70 degrees after BDC, while the exhaust valve duration is from 47 degrees before BDC to five degrees after TDC. The intake valves remain open for around an additional 30 degrees of crankshaft rotation beyond "normal". This kind of valve timing reduces the effective compression ratio from 10:1 to a little under 8:1. Quote Link to comment Share on other sites More sharing options...
///BHRpowered Posted August 17, 2008 Report Share Posted August 17, 2008 Ok saint, remove the supercharger, put regular in and see how it runs, because thats clearly the type of engine you want. its 10 when the fuse is lite so to speak, thats why its officially speced at 8, and since its the same gas you should prepare for the higher numbers. I truely can't understand why people are so obsessed with being a cheap skate on common sense and then bitch about very expensive repairs later on, or the car dying early. Quote Link to comment Share on other sites More sharing options...
latinopikachu Posted August 17, 2008 Report Share Posted August 17, 2008 its not about being a cheap skate, and prove a millenia has ever died due to using a lower octane, until then, i direct your attention to avon.com Quote Link to comment Share on other sites More sharing options...
///BHRpowered Posted August 17, 2008 Report Share Posted August 17, 2008 lat - any millenia sitting on ebay with a blown engine, you can tell it was bought used by a cheap ghetto rat or nappy headed hoe and that was its death. Quote Link to comment Share on other sites More sharing options...
enginph Posted August 18, 2008 Author Report Share Posted August 18, 2008 If you remove the s/c it will not run! Quote Link to comment Share on other sites More sharing options...
Jdubs99 Posted August 18, 2008 Report Share Posted August 18, 2008 I'm assuming the ping sensor is linked to lighting up a CEL from past reading. If that is the case, if 93 were required, we'd have a ton of members throwing posts up here. MTS, didn't you do some kind of number crunch using both fuels? Quote Link to comment Share on other sites More sharing options...
///BHRpowered Posted August 18, 2008 Report Share Posted August 18, 2008 If you remove the s/c it will not run! exactly Quote Link to comment Share on other sites More sharing options...
SteveSter Posted August 18, 2008 Report Share Posted August 18, 2008 So even a KL-ZE wouldnt need premium fuel since its compression is 10:1. Besides octane rating, premium gas does have cleaning additives that keep it clean while regular doesnt. Right? Quote Link to comment Share on other sites More sharing options...
enginph Posted August 18, 2008 Author Report Share Posted August 18, 2008 So even a KL-ZE wouldnt need premium fuel since its compression is 10:1. Besides octane rating, premium gas does have cleaning additives that keep it clean while regular doesnt. Right? I believe it is more of where you buy the gas: http://www.toptiergas.com/retailers.html Quote Link to comment Share on other sites More sharing options...
ing-schu@online.no Posted August 18, 2008 Report Share Posted August 18, 2008 Here most manufacturers of gas add some sort of cleaning additives I believe. Saint is correct, the nominal compression ratio of the Miller Cycle is 8:1. However the always present boost ups it to a resulting 10:1, which in my world means it is wise to run it on at least fairly high octane. Here we have only "midgrade" (95 RON) and up, 98 RON probably is comparable to your premium. There is one supplier selling 92 RON, but that is not recommended in many cars. Here the Miller Cycle is supposed to run on 98 RON or premium. As far as I am concerned, carbon buildup is more related to driving habits than models/engines. Short trip and/or excessive low speed (city) driving is bad. There are however a few cars which reportedly are more prone than others: Mitsubishi 1,8 and 2,4 piece of shit leanburn GDI, also found in some Volvo S40/V40. Ford Zetec fourpots, 1,8 and 2,0, if driven enough under said conditions it can build up enough carbon to practically stop running. Some Volvo 5-pots; same story. That is those I've heard of. I doubt it is gas related. Maybe we have different/better gas? Quote Link to comment Share on other sites More sharing options...
SteveSter Posted August 18, 2008 Report Share Posted August 18, 2008 OK but either way im sure a company like shell doesnt use as many cleaning additives in their regular as they do in their premium. Most of the big gas companies say how their premium gas are formulated to clean out carbon, and gunk deposits left by putting crap regular gas. Why wouldnt they say that about their regular? Quote Link to comment Share on other sites More sharing options...
enginph Posted August 18, 2008 Author Report Share Posted August 18, 2008 OK but either way im sure a company like shell doesnt use as many cleaning additives in their regular as they do in their premium. Most of the big gas companies say how their premium gas are formulated to clean out carbon, and gunk deposits left by putting crap regular gas. Why wouldnt they say that about their regular? Because premium is more expensive. I dont think prem has any more additive than regular. mid is a mixture of regular and prem, it does not even have a separate tank. Quote Link to comment Share on other sites More sharing options...
SteveSter Posted August 18, 2008 Report Share Posted August 18, 2008 The profit margin between regular gas and premium is the same though. I think it would be more effective for a gas company to advertise the fact that their regular gas cleans and protect an engine as well as another gas companies premium gas. Quote Link to comment Share on other sites More sharing options...
///BHRpowered Posted August 18, 2008 Report Share Posted August 18, 2008 you think mid grade doesn't even have its own tank? yes it does, each grade is refined a differently and transported completel seperate, the profit margin is exactly the same, this is because it costs more to make prem, which in most cases has a few cmore cleaners in it to prevent the build up of any carbon the standard higher octane wouldn't remove from a ghetto rat who ran regular through. major gas stations put some cleaners in regular gas, discount stations use less, mexicans use pretty much none Quote Link to comment Share on other sites More sharing options...
ing-schu@online.no Posted August 18, 2008 Report Share Posted August 18, 2008 Yeah right. Here the oil companies certainly add their additives themselves. But a Shell gastruck might just as well supply a Esso gastation and vice versa. Shell have an own grade with cleaning additives, called V-power, availible in both premium (98RON) and midgrade (95RON). I never use it though. But reportedly it does a good job at cleaning. Some brands have blamed the V-power for engine trouble though. Quote Link to comment Share on other sites More sharing options...
mts Posted August 18, 2008 Report Share Posted August 18, 2008 I try to only use Shell. Quote Link to comment Share on other sites More sharing options...
mackin Posted August 19, 2008 Report Share Posted August 19, 2008 you guys are weak for hating on someone for taking good care of their car. you're probably also the fools that don't wash your car because "it will get dirty again after a while" Quote Link to comment Share on other sites More sharing options...
enginph Posted August 19, 2008 Author Report Share Posted August 19, 2008 you guys are weak for hating on someone for taking good care of their car. you're probably also the fools that don't wash your car because "it will get dirty again after a while" Just washed yesterday. I am trying to straighten the rad fins without any process nowadays, any experience? Quote Link to comment Share on other sites More sharing options...
///BHRpowered Posted August 19, 2008 Report Share Posted August 19, 2008 LMAO as much as I want to put a bullet between there eyes everytime I see them they piss me off so much "it'll just get dirty again, and then the rain will clean it" fucking hippies, go back to smoking your shoe laces Quote Link to comment Share on other sites More sharing options...
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