Stock Wheels

A few early Turbo cars were outfitted with a 3-piece Compomotive wheel (4 bolt), while the later cars (most cars) were outfitted with a light alloy BBS wheel (5 bolt).

• 5x120mm bolt pattern
• 71mm center bore
• 15x7 ET+23mm Front
• 15x8 ET-20mm Rear

Stock Tires

• Goodyear NCT
• 195/60 VR 15 Front
• 235/60 VR 15 Rear
• 175/70 SR 14 Spare

Tires on Stock Wheels

Tire Sizing Guide:
A list of common tires that will fit the stock wheels. "# Avail" denotes the number of available H or better rated tires available on Tire Rack (in March '04). Difference is the percentage of the original diameter (this will also affect the speedo reading for the rear wheels.)

Tire	Sidewall	Diameter	# Avail.	Difference
195/60 R 15	117mm	615mm	17	100%
205/55 R 15	113mm	607mm	29	98.7%
215/55 R 15	118mm	617mm	1	100.3%
215/50 R 15	108mm	597mm	5	97.1%
235/60 R 15	141mm	663mm	2	100%
245/55 R 15	135mm	651mm	0	98.2%
245/50 R 15	123mm	627mm	2	94.6%
*255/55 R 15	140mm	661mm	1	99.7%
*255/50 R 15	128mm	637mm	0	96.1%

* Running 255 series is pushing the width limits of the rear 8" wheels.

Aftermarket Wheels

Upgrading to larger wheels increases your tire selection (especially for the rear tires.) It can also give your Esprit a more modern look (or at least "your" look.)

It is a good idea to take good measurements on your car before you start going too far outside the sizes of the OEM wheels/tires. You may end up with tire rub and poor handling if you do not match up the offsets and make sure that your potential wheels clear both the wheel wells (when turning) and the suspension/steering components. Be aware that because of the odd rear offset there are no widely available wheels that will fit the Turbo Esprit.

The other issue at hand is wheel weight. Heavier wheels adversely affect handling and acceleration (of course the corollary is that light wheels improve handling and acceleration.) Cheaper wheels are (usually) heavier due to the manufacturing process (forged vs. billet.) You will be lucky to find 17" wheels that weigh less than 17lbs. (most wheels are 20-22lbs.) You should avoid wheels that are more than 22lbs.

Modular Wheels

There are manufacturers who make 2 or 3 piece modular wheels. These wheels can be made to a variety of widths and offsets. Be aware that you are very limited to the styles of the modular wheels, and they are usually expensive ($500+US per wheel.) Some of the more popular modular wheel manufacturers:

• http://www.kodiakracingwheels.com/
• http://www.usacomp.com
• http://www.imagewheels.co.uk
• http://www.superlite-wheels.com
• http://www.simmonswheel.com.au
• http://www.ronalusa.com
• http://www.kinesismotorsport.com
• http://www.hrewheels.com/
• http://fikse.com/
• http://www.iforged.com/
• http://forgeline.com/
• http://www.compomotive.com/

1982 Turbo Esprit
Image Wheels HT Wheels
16" Front/17" Rear

BMW Wheels

A second option is to fit newer 5 bolt BMW wheels to your Lotus. You have a lot more options when it comes to wheel selection (and much better looking wheels.) You will be limited to 17" and larger wheels (I doubt you would want to go larger than 17".) There are other pitfalls using this method as well.

The first issue mounting BMW wheels to your Lotus is adjusting for the offset. Most BMW wheels are fine for the front (with a positive offset,) but you will need to fit a spacer to make up the difference for the rear. H&R makes a 40mm spacer that will make up the difference (so you can find wheels close to +20ET.) The Esprit uses bolts instead of studs so you will end up with studs on the rear (from the spacer,) and bolts on the front. JAE usually carries the 40mm spacer.

25mm spacer on rear hubs

The second issue is making sure the center bore matches the Esprit. Most after market wheels have large center bores with a hub centric ring that step the bore down to whatever vehicle you are mounting the wheels on. Most BMW vehicles require a center bore of 72.56mm and some require a 74.1mm center bore, so the wheels will probably have a center bore of 74.1 or larger. You can purchase hub centric rings that will reduce the center bore from 74.1 to 70.5 and then machine out the ring to 71mm.

1985 Turbo Esprit
BMW Wheels MHT QWAN
17x8 +20ET Front
17x10 +18ET Rear
25mm spacer on rear hubs

Online shop with staggered and multi-sized BMW wheels
(At least a good starting point)

eBay search for for 17" BMW wheels

Tires on Aftermarket Wheels

Tire Sizing Guide:
A list of common tires that will fit 16" and 17" wheels. "# Avail" denotes the number of available H or better rated tires available on Tire Rack (in March '04). Difference is the percentage of the original stock diameter (this will also affect the speedo reading for the rear wheels.) Keep in mind that to keep the same (or close to the same) stock diameter, the sidewall has to be 0.5" to 1" shorter. Also you should shop for tire pairs that have a similar "overhang" (you don't want one tire bulging over the wheel and the other barely fitting inside the wheel.)

Wheel/Tire Width Conversion Table
Inches	Millimeters	~Min Tire	~Max Tire
7"	177.8mm	195mm	225mm
7.5"	190.5mm	205mm	235mm
8"	203.2mm	215mm	245mm
8.5"	215.9mm	225mm	255mm
9"	228.6mm	235mm	265mm
9.5"	241.3mm	245mm	275mm
10"	254mm	255mm	285mm

Front Tires
Tire	Sidewall	Diameter	# Avail.	Difference
195/60 R 15	117mm	615mm	17	100%
*205/50 R 16	102.5mm	611.4mm	35	99.4%
215/50 R 16	107.5mm	621.4mm	5	101%
225/50 R 16	112.5mm	631.4mm	93	102.6%
**225/45 R 16	101.25mm	608.9mm	6	99%
**235/45 R 16	105.75mm	617.9mm	0	100.5%
*185/50 R 17	92.5mm	616.8mm	0	100.3%
*195/50 R 17	97.5 mm	626.8mm	0	101.9%
*205/45 R 17	102.5mm	636.8mm	13	103.5%
215/45 R 17	107.5mm	616.8mm	50	100.3%
**225/40 R 17	90mm	611.8mm	0	99.5%
**235/40 R 17	94mm	619.8mm	27	100.8%

* Running less than a 210 series is pushing the width limits of a from 8" (203mm) wheel (the tire is almost not wide enough.)
** Running more than a 220 series is pushing the width limits of wheel wells and you may rub on tight turning.

Rear Tires
Tire	Sidewall	Diameter	# Avail.	Difference
235/60 R 15	141mm	663mm	2	100%
215R/55 R 17	138mm	707.8mm	7	106.8%
215R/50 R 17	107.5mm	646.8mm	27	97.6%
225R/50 R 17	112.5mm	656.8mm	14	99%
235R/50 R 17	117.5mm	666.8mm	16	100.6%
245R/50 R 17	122.5mm	676.8mm	8	102%
245R/45 R 17	110.25mm	652.3mm	71	98.4%
*255R/45 R 17	114.75mm	661.3mm	28	99.7%
*265R/45 R 17	119.25mm	670.3mm	0	101.1%
*275R/45 R 17	123.75mm	679.3mm	0	110.5%
*275R/40 R 17	110mm	651.8mm	47	98.3%
**285R/40 R 17	114mm	659.8mm	15	99.5%
**295R/40 R 17	118mm	667.8mm	2	100.7%

* Running more than 250 series is pushing the width limits of rear 8" wheels.
** Running more than 270 series is pushing the width limits of rear 9" wheels.

Performance Tire manufacturers

Some of the more popular tire manufacturers:

• http://www.falkentire.com/
• http://www.bfgoodrichtires.com/
• http://www.nittotire.com/
• http://www.michelinman.com/

Tire Selection Guide

Tires have a shelf life of about 4 years before the rubber begins to harden. This means that unless you are driving your Esprit as a daily driver, you do not need to be concerned as much about tire life as you would with a daily driver. This is beneficial because tire life and tire performance usually have an inverse relationship.

You should be most interested in speed rating (Z) and temperature rating (A). You may actually wish to shop for tire with a low tread wear for your Esprit which usually (but not always) indicates a softer compound that will "stick" to the pavement better than those tires with a higher tread wear.

Tire Speed Rating

The speed rating of any tire is a measurement of the top safe speed the tire can carry a load under specified conditions. It is also an indication of how the tire will handle at lower speeds. A higher rated tire will give you better traction and improved steering response even at 50mph.

The Gold standard for tires is usually considered a "Z" rated tire.

Q	99 MPH, 160km/h
S	112 MPH, 180km/h
T	118 MPH, 190km/h
U	124 MPH, 200km/h
H	130 MPH, 210km/h
V	149 MPH, 240km/h
Z	149 MPH, 240km/h and over
W	168 MPH, 270km/h
Y	186 MPH, 300km/h

UTQG (Uniform Tire Quality Grading)

The Uniform Tire Quality Grading rating is a quality rating system developed by the American Department of Transportation. It is designed to tell consumers the relative performance of passenger tires. Below are examples of UTQG Ratings:

Hoosier R2S03 - This is basically a competition slick (no tread)
40 C A

Pirelli PZero System Asimmetrico - A high performance summer tire
140 A A

Bridgestone Turanze LS-H - An all weather performance tire
400 AA A

Dunlop D65 T Touring - An all weather tire
640 A B

The Treadwear rating is based on a wear test performed on a 400 mile government test course covering specified sections of public roads in Texas. A group of not more than 4 test vehicles travels the course in a convoy so that all tires experience the same conditions. Tread groove depths of the tires being tested are measured after each 800 miles. The same procedure is followed for a set of "control" or "course monitoring tires" Upon the completion of the 7200 mile test, the rating results of both tires are compared, and the tires being tested are assigned a treadwear rating according to government standards. This number can be used to compare between tires. A tire rated 150 should last 1/2 as long as a tire rated 300. The relative performance of tires depends upon the actual conditions of their use and may be significantly different from the norm due to differences in road characteristics and climate.

The Traction ratings are AA, A, B, and C, from highest to lowest. This measurement indicates a tires ability to stop in a straight line on wet pavement. The rating is based on a 40mph test where the brakes are "locked up" on wet asphalt and wet concrete surfaces. It's important to remember that this rating does not indicate the tires ability to resists hydroplaning, and do not apply to cornering traction.

Temperature ratings are determined by running tires on an indoor roadwheel test under specified conditions. Successive 30 minute runs are made in 5mph increments starting at 75mph and continuing until the tires fails. Tires with an A rating must withstand at least 114mph, B at least 99mph, and C at least 85mph. These measurements indicate the tire's ability to sustain high temperatures which often cause tires to wear away quickly or in extreme conditions lead to sudden tire failure.