Very good read. thanks man!!

Yea, a lot of people do ask about wheel spacers, but they simply change the backspacing/offset of the wheel. 1.25" Spacers will decrease a given wheels backspacing by 1.25" and go an additional -32mm on backspacing.

That is pretty neat, but I doubt many people would want to mess with it. As far as the actual speed sensors go, I would never want to mess with them. The main use there is deltas between wheels.

I think many people just run a scangauge or something similar. They usually have a feature to offset the speed/mpg readings...

I know a lot of people run a ScanGauge (not really my thing, they look very ugly and honestly that screen is so tiny and if I really wanted that much data I'd just use a scantool), but the ScanGauge does not adjust the speedometer. I know some people may not mind staring at the tiny ScanGauge screen; but others may actually want their speedometer to read accurately, which the SpeedoHealer allows you to do.

Installing it is pretty easy, you're just giving it a power, ground, and then splicing an input/output between the Vehicle Speed Signal wire to the combination meter. You can do all that at the kickpanel/fuse box area no problem. I just ran mine up at the combination meter because I decided to tap power & ground from the combination meter for a cleaner looking install and simplicity. It also makes it easier for me to test it diagnostically if something happens down the line.

The only reason I brought up the fact that all the SpeedoHealer does is correct the VSS from the Skid Control ECU to the ECM is because technically speaking the Skid Control ECU will still be using the inaccurate vehicle speed data it generated. This isn't as big a deal for ABS (since it cares more about slippage/variance than specific speed); but could have an effect on how VSC & TRAC react since they are managed through the Skid Control ECU and are a bit more complex. The thing is that I don't know exactly how the Skid Control ECUs are programmed; so the newer stuff (i.e. the 5th gens with the "STAR system" and even newer vehicles with more advanced safety features) might actually take Vehicle Speed into account vs. just looking for variances in individual wheel speeds.

Again it's more of a footnote than anything to be seriously worried about to be honest with you; I just felt it was worth noting as a data point.

Right, the scangauge type products do not adjust the actual speedometer, but they do have options to adjust their speed display and calcs for different tire sizes via a correction factor. The scan gauge does have a small screen... There is a cheaper option with a much better screen called an ultraGauge. Think it goes for about $70. It is larger, so the mounting options might be limited....but I have been thinking of picking on up and giving it a try. The speedoHealer sounds like another good option.

I wonder if the speedohealer approach would also correct the center display mpg and the ODO. I'm assuming it would. Most vehicles I've had in the past (with an open ECU...) just let you adjust the tire diameter parameter and everything works as expected. Sort of surprised that Toyota does not at least support this parameter. To me, its like not allowing you to program the tire pressure sensors when you swap those.

I imagine it should, since the other modules get the VSS signal off the CAN bus and/or from either the
ECM or Combination meter.

Hi,

Newbie here, I have read numerous times the enormous information on here for changing wheels and tires and my mind is overwhelmed to the point of wanting to just buy another set of stock tires for my limited rims! I have a 2010 magnetic grey 4Runner with no lift. I hate the "pizza cutters" this truck came with so I want to spring on some new rims and tires and finally have the wife's approval!

So attached is a combination I built on 4wheelparts.com and it consists of BFG All terrain ko2's @ 275/70/r17 and some rims that are 17" 6x5.5 @8" wide with backspace of 4.5" and offset @ zero.

Now the questions

Will it rub?

If so do I need a lift?(planning a spacer lift down the road)

What sort of modifications in the meantime to make no rub?

I can get these rims with 4.75 backspace but they are 9" wide with -6.6mm offset would that be better?

Mostly a soccer mom truck but we do go outback camping in the woods where there is no amenities.


Thanks in advance

Jonathan

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Jonathan, please go back and re read the first post again. It was written as a basic primer for people exactly like yourself. What specific parts of the explanation don't you understand?

Basically the offsets and back spacing requirements. I understand via the 5gen tire fitment guide that those tires in that size are in the "green" for no mods but that presumes stock rims with stock offsets and back spacing. I just don't know how to figure out if they will rub. Mainly what I don't understand is the offset set at 0.
What does that do to the tire at full lock compressed?

I understand stock backspace on the trail edition rims and sr5 rims is 4.5 to 4.875 but offsets are not mentioned in the tire fitment guide? So with my rims I've chosen with 4.5 backspace and 8" wide rim will work , because the 9" rim will not( going back over your original post says many dealers stopped offering them cause of othe issues) with my rim having a offset of 0 matter?

Should work. Might need to push fender liner forward a bit. Really just depends on your alignment... Also, make sure the wheels are hub centric and you get the proper center bore size or adapter ring.

Priceless!

Seriously, thank you @1engineer , @wfo9, @BlackWorksInc , and the many others who make tr4.org both worthwhile and addictive.

Thanks wfo9,

It seems it doesn't matter how far in depth we go in explaining tire and rim upgrades there is always going to be a newbie! I've been following this forum for many a year, owned multiple toyotas and this is my second 4Runner owned from new this one. Original set of tires and 105000kms on the odo. Now it's old enough to put some upgrades into it. I will be doing many other upgrades as I want my now 3 year old son to have this truck for his 16th birthday. I hope there will always be guys like 1engineer and you around to bounce questions off of and Google of course. Will post pics here when installed and also the myriads of magnetic grey threads.

Cheers😀

I use the SG II to adjust my speedometer. It doesn't do anything for the actual speedo in the cluster but my SC is right in front of me and works great. Mine is off 9%.

So this is my combo I went for. Moto metal 970 17x8 wrapped with BFG ko2. 275/70/r17. Had to do the fender liner mod but all is well now even when flexed out. Thanks all for the help. On a secondary note is 12oz of weight normal to balance this rubber? Got them to take the rubber off the rim and the rim is perfect but as soon as the rubber is put on 2 tires are 6.25oz of sticky weights inside the rim and 6.25 oz of clipped on weight on the the backside of the rim for a total of 12.5 on 1 rim! The other two have 3 oz and 2 oz.

i read this before I made my mods but now that I have-it is even better