Modern Vespa

Anyone have any idea why the difference in price between these NGK Iridium spark plugs ( MR8CI-8 vs MRIB7-8 ) and whether it's worth paying the difference? Prices are in Thai Baht.

one has a screw on cap that tends to come loose
the other is a fixed cap

Sorry, my question wasn't clear. The online vendor doesn't stock the expensive iridium plug NGK references for a GTS 300 HPE, but has given the much less expensive iridium plug ( for some Japanese makes ) as a compatible alternative.

This has never been suggested to me by any of the Vespa specialty shops. Has anyone had any experience using this plug? Is the difference in price all marketing?

The terminal ends are irrelevant.
Thanks.

Personally, I don't like paying a Vespa premium for Michelin belts or NGK plugs. I now have it from two online vendors the MR8CI-8 may be used. If you don't hear back from me it works. Wish me luck.

Agreed , No benefit in going for the Vespa brand , but be carefull buying solely on price.

In the UK there is a HUGE counterfeit market in NGK spark plugs.

Who would have thought it, but the mkt must be big enough to attract copies.

Just browse youtube for "counterfeit ngk plugs" and see Iridium plugs feature often

Cheap one is a colder plug compared to the original…

They're both advertised as laser iridium and I've the cheap one on order. It will be interesting to see if it has the same thin (hot) nose of the expensive one.

Can't find the cheap one on NGK's website ...

Yikes. Neither can I. Good point, order has been canceled.
Thanks

The only benefit is that the fancy plugs don't have to be replaced for a long time, which is a factor with a lot of modern cars. The engine bay is so jammed that changing a spark plug is a huge pain, usually requiring hours, special tools and extensive knowledge of curse words. Completely unnecessary for scooters. All plugs last a long time these days, because of lead free fuel, intelligent ignition systems, and machining that means even the cheapest engines are built to tolerances that could only be dreamed about 30 years ago.
Ads and gossip fed to the gullible imply that magic spark plugs somehow increase engine power. All any spark plug does is make a flammable vapor explode. Basic physics tells you that the minute amount of energy in the spark is no more powerful than an ant fart.

ya missed the question: they are both same brand (NGK) same class (Iridium). the q is what is the difference: answer built for different temperatures.

Pal of mine has one of the early water cooled Porsche 911's. To change the six spark plugs its a "take the back" of the car off job. If I was him i would certainly fit Iridiums to reduce the frequency of change.

According to the mechanic I use the difference is in temperature and it's only a difference of one. Says the cheap one may even run better on the hwy.