Finding the right NGK Spark plug for your BMW- is now easy.

[genphreak]

I've been trying to work out the right plugs to get adn found the guides and charts a bit confusing. There's a lot of heresay about what works adn doesn't. Few get specific about the item being discussed, the model, the year; The butt dynoism and debates around statements like 'I changed those out for these and the new ones are excellent' that are constantly continuously comparing old and worn to new are endless.

Now I know we all try, but really half the time we are doing stuff at the same time as doing other things, so the results are clearly all over the place.

To clean this up I did some research. This thread attempts to ascertain which NGK plugs fit early motors, that are not shown in NGK's charts. It will provide pics and details with fitment specs for each type.

Looking at what NGK make available, one can see that all these plugs will physically fit an M42, M44, M50, M52, M54, M60, M62, N62 engine, (inc. the TUs). It is easy to see why aftermarket this can go wrong. A lot of it is because we tend to refer to them by the design types, not by part numbers. And the local part suppliers that are more familiar wth Ford and GM easily mix them up, as do their wholesale suppliers. Then after that, we go fitting them and go blurting about getting mixed results.

Anyway, here they all are, from Latest 'and greatest' to the oldest and 'most proven' w/ pics, applications and indicative pricing. Enjoy!

1: 2: 3: 4: 5:

To suit modern engines in e31, e32, e34, e36, e38, e39 and later:

1a. For M52TU/M54/M62/N62/M73 IX iridium 6418 BKR6EIX .032" $7.83
14mm Thread, 19mm (3/4") Reach, 5/8" (16mm) HexSeat, Resistor, Solid Terminal, ISO Length, Projected Tip, Fine Wire (0.6mm) Iridium Center Electrode, Tapered Cut Ground Electrode, .032" (0.8mm) Gap, Heat Range 6

2a. For M52TU/M54/M62/N62/M73 GP platinum 7092 BKR6EGP .032" $3.15 Comes with .040" (1.016mm) gap?
14mm Thread, 19mm (3/4") Reach, 5/8" (16mm) Hex Size, Gasket Seat, Resistor, Solid Terminal, JIS Height, Projected Tip, Platinum Tipped Center Electrode, Trapezoid (Beveled Cut) Ground Electrode, Heat Range 6

3a. For M52TU/M54/M62/N62/M73 Multi-ground (Quad electode) 3199 BKR6EQUP .032" $8.48
14mm Thread, 19mm (3/4") Reach, 5/8" (16mm) Hex Size, Gasket Seat, Resistor, Solid Terminal, ISO Length, Projected Tip, 4 Ground Electrodes, Platinum Tipped Fine Wire Center Electrode, Heat Range 6

4a. For M42/M44/M50/M60 Multi-ground (Dual electrode) 2288 BKR6EK .032" $5.19 Comes with .035" (0.9mm) gap?
14mm Thread, 19mm (3/4") Reach, 5/8" (16mm) Hex Size, Gasket Seat, Resistor, Solid Terminal, ISO Length, Extended Projected Tip, Dual Ground Electrodes, .032" (0.8mm) Gap, Heat Range 6

4b For M52TU/M54/M62/N62/M73 Multi-ground (Dual electrode) 7969 BKR6EKUB .032" $5.82
Multi-Ground Plug, 14mm Thread, 19mm (3/4") Reach, 5/8" (16mm) Hex Size, Gasket Seat, Resistor, Solid Terminal, ISO Length, Projected Tip, Dual Ground Electrodes, Heat Range 6

5a. For M52TU/M54/M62/N62/M73 V-power 6962 BKR6E .032" $2.89
14mm Thread, 19mm (3/4") Reach, 5/8" (16mm) Hex Size, Gasket Seat, Resistor, Solid Terminal, ISO Length, Projected Tip, V-Power (V-Grooved Center Electrode), .032" (0.8mm) Gap, Heat Range 6

Note: Any one of the above plugs will physically fit an older M50 or M60, but the newer models (Type #1,2 & 3) are NOT reccommended by NGK- let alone BMW in their lists. (i.e. they are only listed for use on the later engines such as M52TU, M54, M62, N62). This does not mean they will not work or provide good results, as we would often like to think they might.

To suit earlier M10, M20, M30 and M70 engines in e21, e23, e24, e26, e28, e30, e32, e34:

1b. For M10 IX iridium 6597 BPR5EIX .036" $7.83
14mm Thread, 19mm (3/4") Reach, 13/16" (20.6mm) Hex Size, Gasket Seat, Resistor, Removable Terminal, JIS Height, Projected Tip, Fine Wire (0.6mm) Iridium Center Electrode, Tapered Cut Ground Electrode, .032" (0.8mm) Gap, Heat Range 5

1c. For M70 IX iridium 2477 ZFR5FIX-11 .032" $7.83
14mm Thread, 19mm (3/4") Reach, 5/8" (16mm) Hex Size, Gasket Seat, Resistor, Extended Projected Tip, Solid Terminal, ISO Length, Fine Wire (0.6mm) Iridium Center Electrode, Tapered Cut Ground Electrode, .044" (1.1mm) Gap, Heat Range 5

2b. For M10 GP platinum 7082 BKR5EGP .036" $3.15
14mm Thread, 19mm (3/4") Reach, 5/8" (16mm) Hex Size, Gasket Seat, Resistor, Solid Terminal, JIS Height, Projected Tip, Platinum Tipped Center Electrode, Trapezoid (Beveled Cut) Ground Electrode, Heat Range 5

2c. For M20/M30 GP Platinum 7102 ZGR5AGP .028" $3.15
14mm Thread, 19mm (3/4") Reach, 13/16" (20.6mm) Hex Size, Gasket Seat, Resistor, Removable Terminal, Extended Projected Tip, Platinum Tipped Center Electrode, Trapezoid (Beveled Cut) Ground Electrode, .040" (1.016mm) Gap, Heat Range 5

2d. For M70 Single Platinum 7098 ZFR5FGP .032" $3.15
14mm Thread, 19mm (3/4") Reach, 5/8" (16mm) Hex Size, Gasket Seat, Resistor, Solid Terminal, ISO Length, Extended Projected Tip, Platinum Tipped Center Electrode, Trapezoid (Beveled Cut) Ground Electrode, .040" (1.016mm) Gap, Heat Range 5

2d. For M70 Double Platinum 3741 PZFR5F .032" $12.06 (Extra Long Life Double Platinum)
14mm Thread, 19mm (3/4") Reach, 5/8" (16mm) Hex Size, Gasket Seat, Resistor, Extended Projected Tip, Solid Terminal, ISO Length, Fine Point Platinum Center Electrode and Platinum Tip Laser Welded on Ground Electrode, .032" (0.8mm) Gap, Heat Range 5

5b For M70 V-power 7558 ZFR5F .032" $2.89
14mm Thread, 19mm (3/4") Reach, 5/8" (16mm) Hex Size, Gasket Seat, Resistor, Extended Projected Tip, Solid Terminal, ISO Length, V-Power (V-Grooved Centere Electrode), .032" (0.8mm) Gap, Heat Range 5

5c. For M10 Traditional 7734 BPR5ES .035"
14mm Thread, 19mm (3/4") Reach, 13/16" (20.6mm) Hex Size, Gasket Seat, Resistor, Removable Terminal, JIS Height, Projected Tip, .035" (0.9mm) Gap, Heat Range 5

5d. For M10 V-power 1233 BPR5EY .035" $2.89 Comes with .032" (0.8mm) Gap?
14mm Thread, 19mm (3/4") Reach, 13/16" (20.6mm) Hex Size, Gasket Seat, Resistor, Solid Terminal, Projected Tip, JIS Height, V-Power (V-Grooved Center Electrode), Heat Range 5

5e. For M20/M30 V-Power 5077 ZGR5A .028" $2.89
14mm Thread, 19mm (3/4") Reach, 13/16" (20.6mm) Hex Size, Gasket Seat, Resistor, Extended Projected Tip, Removable Terminal, ISO Length, V-Power (V-Grooved Centere Electrode), .035" (0.9mm) Gap, Heat Range 5

5f. For late S38 (e34) 3481 DCPR6E .024" $2.89
12mm Thread, 19mm (3/4") Reach, 5/8" (16mm) Hex Size, Gasket Seat, Resistor, Solid Terminal, Projected Tip, .035" (0.9mm) Gap, Heat Range 6

5g. For early S38 (e24, e28) 7912 D7EA .024" $2.89
12mm Thread, 19mm (3/4") Reach, 11/16" (18mm) Hex Size, Gasket Seat, Non-Resistor, Stud Terminal, .027" (0.7mm) Gap, Heat Range 7. NOTE: Does not include terminal nut, if necessary, order part #067606-0051

That said, here is the pfaff from NGK (their explanation of the differnces for all us plebs):

NGK iridium plugs represent the ultimate evolution of spark plug technology and performance. The iridium center electrode is both stronger and harder than platinum. This allows NGK engineers to design an ultra-fine (0.6mm)center electrode reducing the voltage requirement for spark. This allows for a brighter, stronger spark from your existing ignition system. The ground electrode has a tapered cut at the firing end which reduces quenching for better flame core growth and increased ignitability. The combination of fine wire center electrode and tapered cut ground will increase performance, improve acceleration, and fuel efficiency.

NGK G-Power offers the performance and durability of platinum at a competitive price. The center electrode is fine wire platinum for better starts, superior acceleration and better fuel economy. Trapezoid cut ground electrode to reduce quenching.

Multi-ground electrodes improve ignition capabilities and are less sensitive to increased voltage requirements due to gap growth. Designed to specific manufacturer ignition requirements in either supplementary gap, intermittent discharge, or semi-surface discharge, all for various firing tip self cleaning abilities. Platinum center electrode for extended life. Multi-ground plugs maintain all features of NGK's traditional plugs including corrugated ribs, pure alumina silicate ceramic insulator for greater strength and better heat transfer, copper core and triple interior seal.

NGK's unique V-Power design directs the spark to the edge of the electrode where it develops more rapidly, this increases ignitability even in lean burn conditions. In addition the NGK V-Power plug has all the features of their traditional plugs including corrugated ribs, pure alumina silicate ceramic insulator for greater strength and better heat transfer, copper core and triple interior seal.

[Ferret]

You need to be careful with the NGK parts system - they tend to spec the wrong gaps on plugs, assuming that you'll double check them before fitting.

I got caught out - a 1.1mm gap on an M70 or M30 motor will make it run like absoloute crap - especially if your ignition components are old as it creates a much higher break down voltage.

[genphreak]

You need to be careful with the NGK parts system - they tend to spec the wrong gaps on plugs, assuming that you'll double check them before fitting.

I got caught out - a 1.1mm gap on an M70 or M30 motor will make it run like absoloute crap - especially if your ignition components are old as it creates a much higher break down voltage.

Good info, thanks Ferret. There are differences beteen countries I suspect also. The thing I was happy to find was that the spark plugs don't seem to vary much between engine types- that means they are one of the very few things in a BMW that doesn't change at all kinds of random points throughout the production of each model. The point with this list was that- its goes by engine type, listing all the options. Except for the BKR5E, these are a '5' heat range and fit M42/M50+/60+ engines but are the wrong range (and seem to have no real home in the NGK catalogue)

So be sure to check your gaps rather than trust a list. On quad electrode this would not be the case though, its too damn hard I'm sure. But if that is the case with the quad electrode ones, what about dual electode types? Pfft!

[Ferret]

Good info, thanks Ferret. There are differences beteen countries I suspect also. The thing I was happy to find was that the spark plugs don't seem to vary much between engine types- that means they are one of the very few things in a BMW that doesn't change at all kinds of random points throughout the production of each model. The point with this list was that- its goes by engine type, listing all the options. Except for the BKR5E, these are a '5' heat range and fit M42/M50+/60+ engines but are the wrong range (and seem to have no real home in the NGK catalogue)

So be sure to check your gaps rather than trust a list. On quad electrode this would not be the case though, its too damn hard I'm sure. But if that is the case with the quad electrode ones, what about dual electode types? Pfft!

Hah, yeah the problem is that the older engines use coils and distributors, which run at a slightly lower voltage at the plug (as there's also a gap at the distributor.) This means if you use too large a gap, the spark weakens considerably - while the voltage goes through the roof. Because widening the gap does increase the breakdown voltage (see: physics) your ignition system is carrying a much higher voltage through the leads. This means if they were working happily before the plug swap, but are old and knackered - they may well short out with the new higher running voltage.

The later engines, of the M50 era that use coil packs, are much happier to use wider sparks. Having a wider spark is a good thing in general terms, as it makes the air/fuel mix ignite considerably better - but ONLY if you can put the same current through the spark while it has a wider gap. If you widen the gap on an older system, you start to run into trouble because the coil can only dump a certain amount of power into a spark - if you raise the voltage due to the wider gap, the spark weakens as the current has to drop to maintain the same delivered power.

Coil packs are capable of this because they're directly connected to the plug with no distributor gap, meaning more power is applied over the plugs spark gap. If you think about it - a spark plug in a modern engine can have the same gap as an old engine's plug + distributor gap before it needs an uprated coil.

I hope this makes sense?