I have an 09 Ram 5.7. Some sites have the same plugs for an 08. What is the difference between an 08 and 09 Hemi?

 

I run original NGK´s. 2009 Hemi

 

Been doing some looking and it looks like the 08 Rams had a tapered seat and the 09's have a gasket.
Stock - LZFR5C-11
L - 26.5 Reach
Z - Extended Reach
F - (Shell Size) - 3/4" Reach - 5/8" Hex
R - Resistor
5 - Heat Range
C - (Firing End) - Special Design
11 - .044 Gap

 

there are those on here who swear by OEM plugs only for the 09 hemi and that there are problems with platinum plugs and thats why you have to run copper plugs. some have supposedly had problems with platinum plugs and switched back.

That said I put autolite double platinums in mine about 10k ago and havnt had an issue. its the ones that the parts store told me were for my truck.

 

Do you remember the part number iskybantilus?

 

Those NGK Iridium plugs are supposed to be pretty good, but I haven't tried them yet.

 

Sure they may fit as intended by the manufacturer, but the whole reason behind coppers is for reliability, not longevity as with the platinums.

Platinum is only better in marginal situations as compared to copper in every situation. The only downfall to copper is the lifespan. Platinum/iridium do NOT operate at the same temperatures as copper and therefore can cause instability and reliability issue's. OEM programming is designed for copper plugs only.
I did a quick search and found a very easy to understand article without getting into major Physics of it all. I copied this directly from Carsdirect website.

Purpose of the Metal

The metal in a spark plug serves a single basic purpose: to channel the electric energy from the plug wire through the spark plug so that it can be forced to the engine block in the form of a spark. Therefore, any metal that conducts electricity at all could potentially be used for a spark plug. The metal should also not get too hot; one of the main problems with some metals is that they overheat quickly, causing the electric charge itself to be compromised and the spark plug to not operate as smoothly.
Copper Spark Plugs

Copper spark plugs are generally considered to have the best performance of any spark plug type. This is potentially different from what advertising companies suggest, but the other metals are, unfortunately, not as conductive in general as copper is. Platinum and iridium plugs are more likely to overheat, which causes damage to the plug components and can compromise the delivery of the spark to the engine block.
Platinum and Iridium Plugs

Platinum and Iridium plugs perform at a lower level than copper spark plugs, because they are less conductive and they tend to overheat. However, the overall longevity of these two types of metal is better than copper plugs. In reality, copper has the best performance of all three and the worst longevity. Platinum has good longevity and the worst performance. Iridium has good longevity and a performance that is decent, which is why iridium plugs tend to be more expensive than any other type. Still, the difference between these plugs in terms of overall quality is minimal, as there is a trade off for each.
Most copper plugs need to be changed every 20,000 miles or so. Platinum and iridium plugs can often go for twice that before they require changing, but the overall performance will not be as good and you may have to deal with overheating of the plugs. This is potentially not worth the added cost of both platinum and iridium spark plugs, although the decision will depend upon your preference.
If you have any other questions about spark plugs and which are right for your vehicle, consult with a mechanic for more advice.

 

I put the oem ones in at 35k. The ones in it did not look bad at all.

 

i am pretty sure it was APP5325. i just got them from autozone.

I only run copper in my race cars ...because i am worried about performance and i am pulling them all the time to inspect anyway. in my truck i just want them to last a long time. Irridium are better then platinum because the dont hold the heat and hotspot like platinum will. the is a more common problem in boosted applications and nitrous applications, because the hot plug could cause a pre-ignition.

I noticed no difference in performance after changing them over. the old ones looked fine, but i have seen copper plugs foul out or missfire that looked perfectly fine to inspection. i am sure you could run the copper plug a whole lot longer then 30k, and they should function untill the electrode burns off and it cant spark anymore .. but performance will clearly be decrease.

i am not trying to convince anyone to change their mind about what they believe...just saying im using them and their fine for me.

 

I changed mine out at the recommended 30,000 miles as routine service and used the factory plug, NGK SPLZFR5C11. The originals looked pretty good and showed little gap growth at 0.48 to 0.51 inch with some round off of the electrodes. Factory gap is 0.43 inch. Color was good. I know of a few who kept their plugs in for over 50,000 miles and say they didn't have any problems. Based on how mine looked I could see why.

The newer Hemis have two coils in one pack for each cylinder's two spark plugs, thus eliminating the spark plug wires found on the older Hemis. I believe this started in 2009.

Regards,
Dusty

2010 Ram Big Horn 1500 Quad Cab 2WD, 5.7 Hemi, 545RFE, 3.92 LSD, dual exhaust, 20” wheels