On Tue, 5 May 98 09:50:03 +0100 Douglas McKinnie <mup1dm@surrey.ac.uk>
writes:
SNIP
>If I remember the comments from the John Twist tech pages
>correctly, the overdrive is a placebo on the MGB. It does
>no harm to run the engine that fast, and there are no gains
>in either economy or performance. I can imagine that the
>loss of noise might be a large contributing factor in the
>decision to get a high gear, however.
While I won't start the argument over performance with OD/nonOD, I'll
take up the cudgel regarding economy, or at least fuel economy.
Prior to installing OD in the GT, the best highway milage I achieved was
in the 22-25 MPG range. After OD, the mileage has increased to the 25-28
range, and on occasision pushed the 30 MPG barrier.
Granted, there won't be any economy advantage to OD for urban/surbaban
driving, simply cause you don't use it, but on the open road, yes, it'll
save a bit of gas.
Rick Morrison
72 MGBGT
74 Midget
>
>Sorry that this does not answer your question re: choice
>between OD & 5. I'll be asking the same if my 4-speed
>starts giving me any grief, but in the meantime I worry
>less about continuous high revs than I would about an OD
>of unknown pedigree.
The continous "high" revs will do a lot less damage to your engine than
the same number of miles in town. I'd go so far as to say the worst thing
you can do for any engine, is to drive it in stop and go traffic.
Rick Morrison
72 MGBGT
74 Midget
>Douglas McKinnie
>
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