Switching from 14" wheels to either 13" or 15"

[greasymonkey]

My 1990 Super Seven has 14" Panasports, and given the few 14" tire choices, wondering if I should switch to smaller 13" wheels, or go up to 15's. The car is fairly new to me, and came with a set of fairly old Bridgestones. I feel that 15" wheels and tires might add more weight, given I have a Lotus TwinCam and not a more modern engine, I'd rather not give up HP pushing extra weight (I'm already too much weight! )

 

Thanks for any advice/opinions. 

[greasymonkey]

Just now, greasymonkey said:

My 1990 Super Seven has 14" Panasports, and given the few 14" tire choices, wondering if I should switch to smaller 13" wheels, or go up to 15's. The car is fairly new to me, and came with a set of fairly old Bridgestones. I feel that 15" wheels and tires might add more weight, given I have a Lotus TwinCam and not a more modern engine, I'd rather not give up HP pushing extra weight (I'm already too much weight! )

 

Thanks for any advice/opinions. 

 

Sorry, should have added that I just drive the car on the street, and while a track day isn't out of the question in the future, for now, decent handling street tires are my priority.

[MoBoost]

My car has 14” wheels and I’m running Falken Azenis RT660 tires (195/60R 14]. They are reasonably sticky and I find them to be good for road use. 
Available from Tire Rack.

Falken Azenis RT660

[wdb]

I expect you will hear a lot of folks tell you to go with 13" rims for weight savings, if not tire choice. I have 13" wheels on my Lotus twincam powered Caterham. 

[greasymonkey]

8 hours ago, MoBoost said:

My car has 14” wheels and I’m running Falken Azenis RT660 tires (195/60R 14]. They are reasonably sticky and I find them to be good for road use. 
Available from Tire Rack.

Falken Azenis RT660

 

Ah, thanks! I currently have 185/60r14, and meant to ask whether 195/60r14 would fit on the car. So, thank you for your help! I wasn't finding much in 185/60.

[greasymonkey]

6 hours ago, wdb said:

I expect you will hear a lot of folks tell you to go with 13" rims for weight savings, if not tire choice. I have 13" wheels on my Lotus twincam powered Caterham. 

Yeah, I was thinking 13" as well for the same reason. What size rims should I look for in 13"? 

[MoBoost]

My original tires were 185/65-14 and the 195/60-14 were only a slight change in circumference and revs/mile. 
Not sure about the fit on your car. 

 

	tire dia. (in)	tire circum. (ft)	tire revs/mile
195/60-14	23.21	6.08	869
185/70-13	23.20	6.07	869
185/65-14	23.47	6.14	859
185/60-14	22.74	5.95	887

 

[IamScotticus]

The reason for 13's is not for weight saving.  The taller walls you will have with a 165-185 absorb a lot of road and are better in cornering.  

The rubber selection for 13  or 14  is scant regardless.  

I think your 14s are about perfect and I would trade my 3.75 13 minis for 14s any day.

Edited May 31 by IamScotticus

[greasymonkey]

7 hours ago, IamScotticus said:

The reason for 13's is not for weight saving.  The taller walls you will have with a 165-185 absorb a lot of road and are better in cornering.  

The rubber selection for 13  or 14  is scant regardless.  

I think your 14s are about perfect and I would trade my 3.75 13 minis for 14s any day.

I did the math on the tire sizes - 185/60 in both 13 and 14”, and both have the same sidewall height, the only difference is the circumference is an inch smaller. 
 

I’m going to look into the 195/60r14 for fit. 

[greasymonkey]

8 hours ago, MoBoost said:

My original tires were 185/65-14 and the 195/60-14 were only a slight change in circumference and revs/mile. 
Not sure about the fit on your car. 

 

	tire dia. (in)	tire circum. (ft)	tire revs/mile
195/60-14	23.21	6.08	869
185/70-13	23.20	6.07	869
185/65-14	23.47	6.14	859
185/60-14	22.74	5.95	887

 

Thanks, appreciate the info. Mine is a 1990 Super Seven. I’ll get to measuring tomorrow. I think they’ll fit. 

[IamScotticus]

23 hours ago, greasymonkey said:

I did the math on the tire sizes - 185/60 in both 13 and 14”, and both have the same sidewall height,
 

Yes, they would.  The objective is to keep the same external diameter and circumstances.  If you go too large  you have problems with the spare tyre mounting because the center bracket boss (if you have one) is welded in a at a particular height and angle for a certain diameter.  And the speedo issues. Do if you're 165s on 13s, (guessing) you will go down to 155s on 14s. And low profile on 15s.

 

Honestly,  in your situation   with 4.25" PCD, you have so many options in wheels, Id be toying with finding different wheel styles in 14s.  14s good for road and look great.  I got tired of the 13" minis a long time ago.  I'm 3.75" PCD so my options are slim, like 5 cars, ever.  And everything is rare as hens teeth. 

Anyone have any Vega wheels?

Edited June 2 by IamScotticus

[11Budlite]

8 hours ago, IamScotticus said:

I'm 3.75" PCD so my options are slim, like 5 cars, ever.  And everything is rare as hens teeth. 

Anyone have any Vega wheels?

The most common wheels with a 4x3.75" PCD I believe are Triumph Spitfire. There should be plenty of wheels available, either stock or aftermarket aluminum. Vega wheels had a 4x4" PCD like the Sprite/Midget.

[Slonie]

On 5/31/2025 at 4:33 AM, MoBoost said:

My car has 14” wheels and I’m running Falken Azenis RT660 tires (195/60R 14]. They are reasonably sticky and I find them to be good for road use. 
Available from Tire Rack.

Falken Azenis RT660

 

I came here to say that 14" has a way bigger tire selection than 13", at least in this country and for sporty street tires. And also I'm planning to run the RT660s when I get a second wheel set (which will be 14s, for the aforementioned reason!)

[pethier]

I think the Yokohama A052 is the perfect tire for a Seven.  My current Seven has the 6.5x15 Prisoner wheels.  The stock tire size from Caterham is 195/50-15 and the Yokos come in that size.  The A052 tires will stick from the jump at any temperature I plan to drive my Seven in.  I think they are ideal for a Seven for both road and autocross.

 

Now the Yokos are available in 185/55-14.   I just advised a guy with a Honda Beat to ditch the Falkens that rub on his Beat and get the 185/55-14 Yokos.  They will stick better, even if they are smaller and they will not rub on his car.  He is in the same autocross class as I, but I have no interest in keeping him slower.

 

[Slonie]

That's good to hear that the A052 is in that elusive 55-series 14" (I often see 55-series 14" tires on wheels for sale in Japan, but it seems uncommon here). Unfortunately that's the only 14" size but if I'm getting 14s I'll run a square setup anyway. I currently run a 6 front 8 rear setup on 13s.

 

Edit: The only problem with the A052 is $200 per tire in 14", but I suppose speed costs money... how fast do you wan to go? 

Edited June 6 by Slonie

[IamScotticus]

On 6/2/2025 at 7:33 AM, 11Budlite said:

The most common wheels with a 4x3.75" PCD I believe are Triumph Spitfire. 

Yes, that is one of the 5 cars.

[pethier]

37 minutes ago, IamScotticus said:

Yes, that is one of the 5 cars.

Lotus Europa. Triumph Spitfire. Triumph GT6. Triumph TR7.  Triumph TR8.  Lotus 7.  Lotus Elan.  Lotus Plus 2.

[IamScotticus]

1 hour ago, pethier said:

Lotus Europa. Triumph Spitfire. Triumph GT6. Triumph TR7.  Triumph TR8.  Lotus 7.  Lotus Elan.  Lotus Plus 2.

Yes. But those cars may constitue a mere .01% of all available vehicles.  Raise that a little with the '85 RX7.  I could give a list of all the 3.75 cars for N America and UK matkets.. Add the Arial Atom too.

Edited June 6 by IamScotticus

[wdb]

Why do I keep seeing 4x100 for Elan bolt circle? (Mine Elan has knock-ons). 

[pethier]

On 6/6/2025 at 8:52 AM, wdb said:

Why do I keep seeing 4x100 for Elan bolt circle? (Mine Elan has knock-ons). 

Because the source is wrong.  Elans came two ways:

 

Knock-ons:  Not the splines that Rudge wheels used, but pin-drive, as you well know.  I know that with steel wheels you can see the pins poking through.  I am told that one must be careful when offering up an alloy wheel which has blind holes.  If the wheel slips you can drive the pins through the hub.  I don't know for sure if that is really a problem or just a thing Lotusphiles like to repeat.  I do not know if the dimensions of the Elan pin-drive setup is the same that MG used on the MGA Twin Cam (and the pushrod-engined "Deluxe" cars they made to use up the parts when they stopped making the Twin Cam).

 

Conventional wheel studs:  Four stud-and-nut on a 3-3/4-inch circle.  Same as Europa.  The Lotus 47, which looks a lot like a Europa, had knock-on alloy wheels.

 

When I had a Europa, I got four old Spitfire wheels from a guy in Minnesota Triumphs.  I used them with crap tires to hold up the car in the garage over the winter.  I drove the car on 13x6 BWA Sportstar wheels.   I sold that car to a Triumph guy in Mahomet IL.  One thing that attracted him was the wheels:  He had had those on a GT6.

Edited June 10 by pethier