Natey2

2005 LS430, 127K miles.
Original/Factory iridium plugs.
Get about 16mpg, city.

Thinking of replacing them with Toyota Iridium plugs sold by a Lexus dealer on eBay, and ENA coil pack sold on Amazon. Better choices out there?

Thoughts?

Aus430

Is there anything wrong with the current set up? Why do you want to change them?

Natey2

Nothing fundamentally wrong. Just hoping to get better mpg, and routine maintenance/replacement of the spark plugs. Yeah, I know the old adage: if it ain't broken... 😆

Aus430

Better mpg eh? What sort of economy do you get on a decent highway run?

the LS is not great on fuel around slow speed, short distance stop start city traffic but it is reasonable at higher average speed cruising. If you think your ls is using more fuel than it should be, a datascanning obd reader will help you collect sensor readings to see what the computer thinks is going on.

New plugs and coils are unlikely to make much of a difference to your mpgs unless the existing ones are showing problems like missfires.

It can't hurt to refresh plugs per the schedule, roughly every timing belt change. Coils tend to be either they work fine or they don't and you have a noticeable missfire on a cylinder or two. There is no point changing coils unless one breaks ( if ever), or modifying the engine with something like a supercharger.

Aus430

Just reread your original post, When you say original factory plugs - as in never changed? Then yes it would be a good idea to put new irridium plugs in as per suggested maintenance schedule.

Romanova

Don't replace the coils, that's just a waste of money. Replace the plugs with OEM due to mileage.

bradland

The price alone of the ENA product speaks volumes but did you read the reviews explaining VERY short longevity? There's really no need to replace them if firing normally. If that happens choose Genuine Toyota or either NGK or Denso from Rockauto. As mentioned above coils are generally either good or not. Quite often coil failure is caused by a compromised tube seal which allows oil to pool around the coil. Tube seals are only a few dollars each but they are somewhat labor-intensive. Cheap insurance if you are replacing spark plugs.

Striker223

My 430 has 237k now, on original coils and 6 of them were covered in oil when I got the car from failed valve covers. I doubt you need new ones

TominPT

When I replaced my plugs in my '05 at ~115,000 miles it made absolutely no difference in fuel economy. Original plugs looked good and gap was close to spec. Assuming your engine is otherwise in tune and healthy the best way to get better economy is driving habits (makes a big difference in my experience) or combine trips to have fewer cold starts. 16 mph city is not that bad, frankly. Make sure your air filter is clean and do the usual maintenance, clean the MAF sensor, use synthetic oil, inflate the tires to proper pressure, etc.

Natey2

My mpg attached.

LS430 mpg

TominPT

^ Motor on. Nothing to see here, normal for city or mixed driving.
https://www.fuelly.com/car/lexus/ls430/all