Delica Canada | Mitsubishi Van Club

Curious as to what the 100kmh cruising RPM should be in 5th gear on a manual 2.5TD? It has slightly oversized tires - 30s I believe.

I'd be curious what it is for the automatic with stock wheels as well. Maybe with od off too? I think my tach is off a bit.

Butch from CVI in Richmond got back to me. Said 3k at 100kmh in the manual is normal. Seems high, wondering if there's a way to swap out for a taller 5th gear for highway driving? I downshift on anything more than a small hill climb anyways, so it wouldn't be a big deal and would only be for flat road cruising.

jHands wrote:Butch from CVI in Richmond got back to me. Said 3k at 100kmh in the manual is normal. Seems high, wondering if there's a way to swap out for a taller 5th gear for highway driving? I downshift on anything more than a small hill climb anyways, so it wouldn't be a big deal and would only be for flat road cruising.

If im remembering right I think im at 3500 right around 75mph/120kmh. And ive maintained that for long periods of time on some long road trips, engine doesnt seem to mind, temp stays low. if theres much of a hill or headwind i'll cruise closer to 100kmh to avoid putting much strain on it and bringing the temps up.

Though i have just under 32" tires so thats probably closer to 80mph at 3500

Been driving my manual for years, 3000rpm@100kmh is the norm. My understanding is options for a higher fifth gear dont really exist, but I'd be interested if it did. My best fuel economy is cruising 90km/h@2750 rpm, thats the sweet spot

I'm not sure why the manuals got such a weird diff ratio.It makes sense for a petrol engine, but it seems a bit low for a diesel.
There's a handy calculator here:
http://www.osella.com.au/gear-ratios.htm
...which you can use to figure out what RPMs you'll be doing with different tyre diameters.

Relevant data:
Manual 4wd L300 Diesel: diff ratio 4.625:1, 5th gear ratio 0.856:1
Automatic 4wd L300 Diesel: diff ratio 4.875:1, Overdrive ratio 0.688:1

Stock 215R15 tyres are about 666mm diameter when loaded
31" tyres are 706mm diameter
(Source: https://www.errolstyres.co.za/content/t ... g-diameter)

So fitting 31" tyres to your manual would drop you from 3170rpm at 100kph to 2990rpm. Woo.

Growlerbearnz wrote: So fitting 31" tyres to your manual would drop you from 3170rpm at 100kph to 2990rpm. Woo.

Cool! I plan on going with 30x9.50s as I understand 31s will rub. But I did notice at 100 kph the RPM are up there. Now to disable the darned speed warning chime ...

Crankshaft Culture wrote:
Now to disable the darned speed warning chime ...

That one's easy. It's on the back of the instrument cluster, and is connected by a couple of wires which are easily detached.

Growlerbearnz wrote:

Crankshaft Culture wrote:
Now to disable the darned speed warning chime ...

That one's easy. It's on the back of the instrument cluster, and is connected by a couple of wires which are easily detached.

Very good! I'll take a look at that.