Not your average spark plug question thread. (1 Viewer)

[3rdgen]

Hi everyone.

I just acquired an 03 sequoia. My question pertains to the 2uz so I thought I would post in the 100 series forum since it appears to have more activity and obviously some purists than other toyota forums. I have searched and have seen the regular/premium gas performance MPG threads and which spark plug threads but nobody seems to reference the tundra/sequoia as a comparison.

My question is, does anyone know why are there difference in spark plugs between the 2000-2004 100 series LC and and 2000-2004 Tundra/Sequoia? For instance, the spark plug recommendation per the LC manual is SK20R11, Long Life Iridiums with a .044 gap. For the Tundra/Sequoia its the K20R-U with a .032 gap.

Going a step further, I looked into the coil pack part number from toyota. There appears to be a change in part number based on Production date in 2003 but the coil pack part number from toyota for a 2002 LC and a 2002 Tundra/Sequoia are the same and for a 2004 LC and Tundra/Sequoia they are the same. 2003 goes either way based on production date for both models. And one more step after that, the LC and Tundra/Sequoia use the same upstream o2 (A/F) sensor for 2000-2004. So Im thinking its NOT a made in Japan made in the US thing.

I currently have both spark plugs in my garage. Im was going to put in the SK20R11s but thought I would ask first before I did.

Thoughts?

Also 2000-2004 octane recommendation for the tundra/sequoia is 87. For the LC it is 87 as well. However, the LC manual goes a step further to state that for better performance to use premium (91/93). Any thoughts on this as well? Im in the Midwest and currently running 87. For my CO trip next week, Im thinking of running premium.

Does all of this just due to marketing? The LC/LX being seen as a premium upscale model with the recommendation of more expensive maintenance as to the tundra/sequoia being more budget friendly? If you can afford a $60K LC/LX then you should be able to afford $8 spark plugs and higher gas prices mentality from Toyota. But at the same time, I think its cheaper to replace the SK20R11 once every 100k miles vs K20R-U every 30K miles based on recommendation.

I have crossed my mind a few times trying to figure this out.

 

[bulax99]

I would stick with what your truck specs tell you to use. The fact that the spark plug gaps are different, along with the coils part numbers, either mean a engine spec change for use in the tundra, or an engine revision at some point. The octane requirement for your truck also points to a change in specifications for your truck. Our LCs definitely require premium and affect gas mileage if not used. Being able to burn through a tank of gas on the freeway will give you the info you need to decide which octane will suffice. HTH

 

[3rdgen]

I apologize for the confusion. The coil packs are the same part number for both the LC/LX and the Tundra/Sequoia. A 2uz is a 2uz. What make the 100 series 2uz different if at all. From what I have have been able to find, it appears that you can take an 2uz from a Tundra and drop it in a 100 series and nobody would be able to tell the difference in performance. Im just wondering if someone knows something that I am overlooking.

 

[2001LC]

The 100 series from 98-07 all have the 4.7 2UZ-fe. But through the years there are differences. The biggest is the addition of the VVt-i in May of 2005. In 2000 they made some changes, again in 2003 came more changes/difference. I just learned yesterday of a change in the PCV hose on the left side for the 2000, with mfg date of 2000 June vs pre june. That a small change but gives you and idea how it was constantly evolving.

You can swap long block, but must stick with one's VVt or non VVT long block and setup. Additionally even swapping 100's non VVT with different year 100's non VVT one may need to swap other parts like throttle body, etc.

I've been doing a lot of digging on the subject of which is better Japanese built vs USA built engines. What i've found is they are the same. Most believe the connecting rods are different, they're not. Some say the USA built 2UZ-fe developed a knock or piston slap (after warm up). My findings indicate chances are the same in either. They all have some piston slap when cold.

Some of the coil changes are because of manufacturing of coil change some is do to the variation in engines most notable the VVT's coil.

Oct rating change with years also, but we can run either as long as we don't hear a ping. But it does drop MPG with 87 just a tad, here in the mile high city.

But the spark plugs for all years (2UZ-fe) are the same SK20R11 Iridium. Check with Denso for your application, the Iridium is the long life which is what's recommended for the 100 series to get 100K or more. They now have some 0.4mm Center Electrode http://densoautoparts.com/spark-plugs.aspx I'm going to try.

Try the SK20R11 iridiums in you're rig, it should be fine. You'll soon know if any issues.

Come back and lets use know how it works out.