Personally I dont think 1mm makes one hell of any difference, I mean really? Do you know how small 1mm is?
That being said I have the 8mm wires because they were only $5 more so why not?

 

I can send you a picture showing that my 8mm wires fit just fine in the factory wire holders.
You can also use the 8mm STI wires from British Parts of Utah for $70 a set.

 

Not everyone.
I've switched from Magnecore to Kingsborne, 1/2 the price for good wires.
They also sell wire separators that 8mm fit well in.
Wires
http://www.kingsbornewires.com/produ...&categoryId=38
Separators
http://www.kingsbornewires.com/categ...?categoryId=88

 

WOW!!...even less than half....$35 for 8mm.
are they working well for you?
it says they have screw on coil connectors...do the LR wires screw on or push on?...i know they have "ridges" , i thought this was for a good fit...not sure if i should have "screwed" them on.
thanks muchly for the link...i may go with these....$ is an important factor for me now.....in the "ole days" i just used to buy the most expensive...DUH!

 

just ordered 8mm yellow + wire holders....with shipping total was $56.
thanks again for the link...very kind!

 

No, they just push on. I've got the Kingsborn wires and no problems so far.

Eric

 

I have had the Kingsborne 8mm and the STI 7mm honestly I prefer the STI I noticed that the Kings had given me an odd radio wine... The 1mm difference is not enough to matter in our motors... Now on my Corvette I run 10.5 Taylors but that is a high compression fire breathing bad ***... The Rover is just a daily driver with the capabilities to do much more... lol...

On the 8mm point also I work for a Rover repair shop in Denver and we have had many trucks come in with 8mm wires that for some reason or another are arcing and I have never seen a 7mm wire come in with that issue... Actually we have swapped wires on many Rovers from the 8mm to the 7mm just testing because there is a missfire and that has solved many of those customers problems... Just something to think about...

 

This is VERY valuable info in only we could prove it.
Many many many many people have done a complete tune up on their DII and afterwards have a mis fire that cannot be solved.
They always leave the forum to never be heard from again after replacing the coils and having the problem remain.

 

I can't see any reason an 8mm would cause a problem where a 7mm wouldn't, comparing the same brand.
I can see where 8mm might come loose from the separators and lay against metal parts and/or each other and leak current.

 

maybe you get many customers having problems with the 8mm because they are forcing them into the 7mm holders, i like the idea in this thread with using dielectric grease to ease them in, but i still prefer a "correct" fit, so i just bought the correct holders.