Date: Wed, 14 Jul 2021 22:14:54 -0600
Reply-To: Jon VO <jondvo@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Jon VO <jondvo@GMAIL.COM>
Subject: Re: Taller tires with Subie 2.2?
In-Reply-To: <CY4PR0801MB3731604BA2E654D7C0CA0E6FA0129@CY4PR0801MB3731.namprd08.prod.outlook.com>
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I have used 205-65-16 Nokian tires that have adequate load capacity
(index 103). They will fit in the stock spare location. Had to change as
the big brake mod required more clearance than steel 16in Mefro wheels.
Currently running 215r60-16 Nokian Cline. Fairly close to stock or
195R-14 diameter ( spares), not close enough for syncro use. Syncro's
require pretty much identical rolling diameter for all 4. I really wish
I could find 16in alloys 6.5in wide...ALL the alloys I locate are 7.5 or
wider - too much for Vanagon IMHO.
Jon
On 7/14/2021 7:24 PM, Dennis Haynes wrote:
> Having 16 inch wheels regardless of engine or gearing I think the ideal fit is 225/60-16. This size is just about an inch taller than stock so it is good trim fit. It won't rub on anything and the load capacity is adeaquate in native form (load index 98) and readily available in XL (load index 101). You can also get a 205/65-16 for a spare so that the spare will accommodate future big brakes.
>
> One advantage of the 2.2 is the CARB approval (thanks to Kennedy). A major part of the CARB approval is based on NOx emissions, think VW and the Diesel scandal. It takes a combination of torque and speed to make horsepower. As you reduce RPM torque has to increase proportionally, which from the engine means increased cylinder pressures which is the start of NOx production. Next is the increased pressure and load on the gearbox. No free lunch. Fuel savings would be negligible. Overall I find the transmission is much more of a waek link than the Waterboxer.
>
> Dennis
>
>
> -----Original Message-----
> From: Vanagon Mailing List <vanagon@gerry.vanagon.com> On Behalf Of Richard Koerner
> Sent: Wednesday, July 14, 2021 8:03 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Taller tires with Subie 2.2?
>
> I am currently running 215/60R16 tires on my 85 Tintop with manual tranny. My trusted mechanic is encouraging me to move up to 215/65 or even 215/70; he says the Subie motor has plenty of power to handle the bigger rubber OD. But I am not so obliged, here is my reasoning: Number 1, I drive a LOT of twisty mountain roads and sometimes that include a long grade prior; I totally love the response and performance when in these situations, one of the main reasons I did the conversion. Number 2: Being a little OCD, having the speedometer and odometer even further off than currently (example, 62 Speedometer vs. 65 GPS) would just bug me. Number 3: Braking....yep, the larger rubber OD means reduced braking ability, simple mechanical advantage situation. Number 4: Rotational Inertia of more heavy rubber further away from rotational axis means harder to get going and harder to stop, so a little harder on motor and a little harder on brakes...I know, I'm getting a little picky on this one.
>
> Sure, there might be some MPG gain (not that important to me, as it is I get a reliable 22 MPG on roadtrips). Sure, when freeway cruising on long flats, could probably maintain higher speed, but that might be offset by frontal wind resistance which goes up by the square of speed, non-linear. There might be some engine or tranny wear issues due to some lugging in some circumstances, and I know that is a no-no; Subie motors from what I have heard due to their fine balance and strong metallurgy are fine with running 4000 RPM for hours and hours at a time.
>
> These are my current thoughts. Any input? Something I'm missing? Whatever the cost difference between the tire sizes is pretty negligible I'm thinking. The driving experience is primary, followed by the longevity of motor and brakes and tranny is my main concern.
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