Thought this might be useful for those who were looking to change their tires. I used a 3% limit to weed off unsuitable tires. The first *column* is the tire size; second is total height,in inches; third is deviation from stock, in inches; the fourth is deviation from stock in %.

The first *line* is the stock Lightning tire.

295/45x18----------28.45----------n/a--------------n/a
305/45x18----------28.81------------ 0.35----------1.25%
305/40x18----------27.61------------ (0.85)----------(2.97%)
315/45x18----------29.16------------ 0.71----------2.49%
315/40x18----------27.92------------ (0.53)----------(1.87%)
315/45x18----------29.16------------ 0.71----------2.49%
315/40x18----------27.92------------ (0.53)----------(1.87%)
295/40x19----------28.29------------ (0.16)----------(0.57%)
305/40x19----------28.61------------ 0.15----------0.54%
315/40x19----------28.92------------ 0.47----------1.65%
315/35x19----------27.68------------ (0.77)----------(2.71%)
295/40x20----------29.29------------ 0.84----------2.95%
295/35x20----------28.13------------ (0.32)----------(1.13%)
305/35x20----------28.41------------ (0.05)----------(0.17%)
315/35x20----------28.68------------ 0.23----------0.80%

Tires may not be available for all the sizes above.

Hope its useful. If the table comes out garbled or in any way difficult to read, email me and I can send it to you in excel or word/notepad.

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Thunder
rainmaker@attglobal.net

Black 97 Expedition EB 5.4L 4WD

Mods: Lightning Wheels, Pirelli Scorpion Zero 285/55/18, K&N Gen II Kit, JET Chip

Audio: McIntosh MX406, McIntosh MCD4000, Zapco SX-SL, Zapco EQ30, Genesis Monoblocks (3), Genesis Dual Mono, Dynaudio System 340, Dynaudio System 220, JL Audio Stealthbox


[This message has been edited by Thunder (edited 01-10-2000).]

[This message has been edited by Thunder (edited 01-10-2000).]

[This message has been edited by Thunder (edited 01-10-2000).]

 

Thunder -

Gotta number for a 275/40ZR17 drag radials. I know it is considerably smaller, but just curious what the exact numbers would be..

Thanks for the help.

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1999 Black Roush-Lowered Lightning - w/Super Chip (YEEEOW!), JBA Headers, Power Surge air kit, AAD Cobra hood, carbon fiber dash kit, CD Changer, Towing Package,Grey Rhino, clear corner lenses.
http://www.zing.com/picture/ff/ea/96/8/ffea9683.jpg


[This message has been edited by sixpipes (edited 01-10-2000).]

[This message has been edited by sixpipes (edited 01-10-2000).]

 

No prob. Is this for slicks?

Total width is 10.79 inches
Sidewall height or aspect is 4.31 inches
Overall height is 25.63 inches
Which means those tires would be off (smaller) by 2.82 inches or 9.92%.

------------------
Thunder
rainmaker@attglobal.net

Black 97 Expedition EB 5.4L 4WD

Mods: Lightning Wheels, Pirelli Scorpion Zero 285/55/18, K&N Gen II Kit, JET Chip

Audio: McIntosh MX406, McIntosh MCD4000, Zapco SX-SL, Zapco EQ30, Genesis Monoblocks (3), Genesis Dual Mono, Dynaudio System 340, Dynaudio System 220, JL Audio Stealthbox

 

Which Drag T/A would be better?

275/60R15
295/65R15
315/60R15

These seem to come closest in overall diameter to the stock F1s, as far as the T/As go.

Also what is this about maximum load being in the 2000-2500 lb. range? Is that okay for our trucks?

Just read that Nitto has new 245/45R17s, seems to be their biggest DR, still too small?

Thanks,
Mike


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99.5 Black Lightning
PowerSurge Cone Filter
JBA Jet-Hot coated headers
Flowmaster muffler
So-Cal Lowering Kit; Cal-Tracs traction bars
Watter Wetter
Lo-Jack



[This message has been edited by BRIMSTONE (edited 01-14-2000).]

 

Better in what sense? Getting power to the ground? Then I guess your best bet will be to go with the 315/60R15s. If you want to maintain the stock diameter, the 275/60/15s are the ones. If these tires are have more grip, hopefully that offsets what you lost by going with thinner tires.

My only other concern is that tires with taller sidewalls normally aren't as stiff and lower profile tires...which relates to your next question.

The load rating...hmmm...I'm not sure how heavy the Lightning is but my guess is that it should be fine for the straight line. The load affects the tires during cornering more than anything else because cornering is what gives the sidewalls the maximum loads.

Using the nittos would leave you off by almost 10% or almost 3 in. lower at the rear (I'm assuming you are only replacing the rear tires) which would tend to make the L's rear lower than the front. That can't be too good.



------------------
Thunder
rainmaker@attglobal.net

Black 97 Expedition EB 5.4L 4WD

Mods: Lightning Wheels, Pirelli Scorpion Zero 285/55/18, K&N Gen II Kit, JET Chip

Brembo 14" disc brake kit coming right up!!!

Audio: McIntosh MX406, McIntosh MCD4000, Zapco SX-SL, Zapco EQ30, Genesis Monoblocks (3), Genesis Dual Mono, Dynaudio System 340, Dynaudio System 220, JL Audio Stealthbox

 

Thunder -

What's the diameter on a 275/60R17 tire?

Thanks

 

http://www.miata.net/garage/tirecalc.html

30"

[This message has been edited by MRBBQMAN (edited 02-20-2000).]

 

Egad - This was a "normal" exchange.

Thanks

 

If you're looking at 17" tires, a 275/55R17 tire would be closer to the original oem diameter at 28.91. It's only 1.61% off the oem diameter of 28.45. A 285/50R17 would be closer still at 28.22, off only by -0.82%.

The 275/60R17s are almost 5.5% off.


------------------
Thunder
rainmaker@attglobal.net

Black 97 Expedition EB 5.4L 4WD

Mods: Lightning front fascia, Lightning Wheels, Pirelli Scorpion Zero 285/55VR18, K&N Gen II Kit, JET Chip

Brembo 14" disc brake kit coming right up!!! And hopefully a Lightning engine too!!!

Audio: McIntosh MX406, McIntosh MCD4000, Zapco SX-SL, Zapco EQ30, Genesis Monoblocks (3), Genesis Dual Mono, Dynaudio System 340, Dynaudio System 220, JL Audio Stealthbox

 

yeah, "weird" wasn't it?
i can assure you, there is nothing normal going on over on my end.

 

Just to let you guys know, and possibly save you some $$ and headaches, you can't fit a 15" rim on the 99-up Lightning. It won't clear the brakes. Been there, done that...

------------------
SAL (E-mail- PowerSurgePerf@aol.com)
13.35@103mph
All stock with PSP 99 Lightning Chip and Filter Kit

Power Surge Performance--- Your SOURCE for SVT Lightning EFI Tuning and Performance!! http://members.aol.com/NLOCsvt/svt.html

 

Tallest current drag radial that I could find is BF Goodrich Comp T/A Drag Radial size P255/50R 16. It is 26.1" in diameter. I believe several members of this board are using this tire successfully.

dsc@home.com

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1999 Black, Superchip, Bassani, PSP Filter, 4:10 Downs, ARE

SVT# 2917 DOB 7-26-99
Northern CA, 98 Gold Lexus GS 400, 67 Pearl White Nova