Mileage in my truck is crap. One of the many things I am changing to hopefully help us plugs. Is there any advantage to the fancy stuff or are the cheap Delco plugs good?
Copper? Platinum? Irridium? Delco? NGK? Denso? Bosch? Too many options.... Leaning toward an NGK platinum for about $3.50/ea.

What truck do you have?

Many of today's cars/trucks come with 100,000-mile plugs. Unless you have a car that's over 20 years old I would stay with whatever the manufacturer used. Buy the exact same plug IMHO.

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Originally posted by comet24:
What truck do you have?

Many of today's cars/trucks come with 100,000-mile plugs. Unless you have a car that's over 20 years old I would stay with whatever the manufacturer used. Buy the exact same plug IMHO.

+1. Spark plugs are one of the few items I’ll stick to OEM for on a modern engine. If yours is old, all bets are off. And yes, NGK makes excellent plugs, so does Denso and Bosch, for the most part. Also, copper is cheap, platinum is much better, and iridium is the best, generally, depending on your engine.

-Rob

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Many of today's cars/trucks come with 100,000-mile plugs.

In my old Silverado, I changed the plugs at 100,000 miles. After a few tanks of gas, I looked at my mpg spreadsheet and realized I should have changed them between 96 and 97 thousand miles.

As far as the OP's question, hotter plugs only make a difference if you're running rich or if you have a tuner where you can tweak settings to take advantage. If you're running rich, you'd be better off figuring out why instead of buying fancier spark plugs.

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Originally posted by wolfe 21:
Mileage in my truck is crap. One of the many things I am changing to hopefully help us plugs. Is there any advantage to the fancy stuff or are the cheap Delco plugs good?
Copper? Platinum? Irridium? Delco? NGK? Denso? Bosch? Too many options.... Leaning toward an NGK platinum for about $3.50/ea.

Why so many plugs? Because there's a market, and there are a lot of types of plugs, with regard to reach, heat range, resistance, etc. Most of the spark plugs make claims that don't amount to much.

New plugs will help if your old are worn, out, but if they're not, then simply regapping is about as much as you'll get.

Check timing, vacuum leaks, and condition of your distributor and rotor. Check engine compression, and see where it's leaking. Through the breather (rings and cylinder wear), through the exhaust (exhaust valve), through the oil filler cap (valve guides), through the radiator (head gasket), or through the induction/intake (intake valves). Fuel filters good? Injectors clean and functioning? Carburetor clean and tuned? Thats about it for the engine. Air filter clean?

Brakes dragging? Tire pressure good?

That's about all you can do for mileage.

01 s10 with a 4 cyl. At 18 model years and spending more time sitting than running, I figured the $15 for plugs was worth it either way and probably past due. Ignition is coil on plug, no distributor or rotor to fail.
Not looking to change heat ranges or anything fancy. I doubt it's worth it. Probably makes 80hp to the wheels. Just new stock style replacements. Will check vacuum lines as well, but I'm not getting any idiot lights.

If you have a 10 year or so old vehicle, there may well be ‘better’ plugs available than those listed in the maintenance manual, or removed.

I recommend sticking with OEM brand plugs - AC/Delco for GM, Champion for Chrysler, Motorcraft (Autolite acceptable) for Ford, NGK or Denso/Nippondenso for Japanese, and so on. Avoid gimmicky" plugs that claim to increase power and mileage all by themselves such as Splitfire (if they are still around). In vehicles other than Chrysler, Champions have caused misfires and other strange running problems that mimic a vacuum leak. When I put the OEM-brand plugs back in the problems stopped. If it calls for a standard plug I see no harm in upgrading to a platinum of the same brand. Speaking of platinums, the Bosch with the porcelain center electrode that comes to a point with no metal visible aren't worth a shit. Every time I have tried them, or seen them tried, they caused misfires.

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Originally posted by comet24:
Many of today's cars/trucks come with 100,000-mile plugs.

Ya know why? Because the designer/engineer rejects that build new cars put the damn things in a position, or under so much stuff, that you can't get to the plugs without four extensions, a couple of universals, and a first aid kit.

I've got a 2001 F150 and replaced the stock plugs with newer NGK's. Truck runs well, but the mileage didn't improve a bit.

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01 s10 with a 4 cyl.

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Ignition is coil on plug

Not on plug. Distributorless, yes, but it still has wires. If you do your plugs, have new wires on hand, because on this engine they are stuck on tight and difficult to get a grasp on. You'll probably jerk them out by the roots.

I have a vague recollection of you complaining about the power and mileage of this truck before. The GM "122" engine, as it is known, is low tech even for GM, and not much can be done with it over and above being sure it is in good working order.

This message has been edited. Last edited by: egregore,

IMO, plugs is plugs. Fancy materials may last longer, but don't mean squat to MPG.

If you plan on keeping the vehicle, I would do the wires if they have never been replaced and plugs. As far as plugs just use what is specified in the owners manual unless you want to increase time between plug changes. If you vary from oem you could experience issues or could be just fine. Some of the vacuum hoses my 03 s-10 were shot around 2012 due to being rubber and not silicone. Check the line that goes to the vacuum canisister in wheel well (looks like a coffee can), if your model year has that same equipment. If your truck idles properly you probably don’t have any vacuum leaks.

I read this post late last night. After 1 1/2 hours I ordered the OEM AC Delco Iridium plugs and new wires. While I only have 87,000 miles on my 2010 Silverado I tend to do PM a little early. So many choices. I must have read a few hundred reviews. What helped most was the truck forum that I belong to. There seem to be quite a few problems when people switch from OEM to different brands.

OEM...same brand, same type. I bought some fancy aftermarket plugs for my 01 Silverado with 200k on it one time, and had all kinds of misfires and shuddering. The new "fancy" plugs were worse than the original plugs that they replaced. Switched them out for new OEM AC Delco Irridiums and all the problems went away. Expensive lesson, but now I know and I won't make that mistake again.

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Originally posted by egregore:

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01 s10 with a 4 cyl.

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Ignition is coil on plug

Not on plug. Distributorless, yes, but it still has wires. If you do your plugs, have new wires on hand, because on this engine they are stuck on tight and difficult to get a grasp on. You'll probably jerk them out by the roots.

I have a vague recollection of you complaining about the power and mileage of this truck before. The GM "122" engine, as it is known, is low tech even for GM, and not much can be done with it over and above being sure it is in good working order.

Yeah, I like the design in general. Have been driving them for 15 years. This particular example, though, I am just about done with. Paired to the Auto trans, it is even worse than average. I have been shopping around, but.my desire to avoid a car payment has kept me in this particular POS.

I will look for Delco plugs on my next trip to the parts store. Wires as well, as this is not the first time I've heard they are a pain. Might upgrade to the platinum model.

I have a recollection of removing the wires from the coil end by jacking the truck up, taking the right front wheel off and going in through the wheel well. Otherwise you have to do it by feel. For some reason that inline four still manages to take up all the space in the engine bay.

Yeah, not at all like my first car. I could set in the engine bay and work on stuff. I don't know how guys stuff LS engines into these things.

Just stick with what is suggested from the factory and you'll be fine (IE Copper/Platinum/Iridium)

Good quality tools shouldn't be overlooked when doing this. Get a magnetic spark plug socket, or just wish you did.

Don't forget the anti-seize.

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Originally posted by comet24:
What truck do you have?

I'll answer for him. It doesn't matter what truck he owns.

Today, and for the past 20+ years, your best bet almost always, is to put the EXACT same plug in that came out. With very few exceptions (like exploding Ford plugs), this is the correct plug for the vehicle.

Get a set of OEM plugs, and change them.

If they are long life Iridium or similar, then yes, it is ok to change Iridium plugs every 100K miles or so. I change them at 90K personally, and they come out perfect.