upsize my 14" rims to 16" What can I expect?

Submitted: Sunday, Jun 29, 2003 at 20:43

ThreadID: 5728 Views:2236 Replies:6 FollowUps:2

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Ian

I am in the final stages of upgrading my Mitsubishi L300. I putting in a 2600 Astron motor,done the suspesions, heavy duty clutch, brakes, second battery etc but what I would like to do is replace my standard 14" rims with 16" rims for increased ground clearance. So far nobody can agree on the result.
Do I get better or worse economy?
How is my power effected?
What about towing?
If you can answer any of these questions I would be grateful. I would also like to know why as I have so many 'experts' with varying opinions.

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Reply By: desert - Sunday, Jun 29, 2003 at 20:50

Reply By: phil - Monday, Jun 30, 2003 at 08:32

Monday, Jun 30, 2003 at 08:32

The increased power and torque of the 2.6 Astron motor will, at least partly, cancel out the taller effective gearing from the larger tyres. Given that many older utes had rather low overall gearing the result may allow much more relaxed highway cruising. However you may find it difficult to crawl slowly over rough and steep terrain. I can not see why fuel economy should suffer , in fact if the engine is revving less at highway speeds, and has sufficient power, it should improve.
Phil

AnswerID: 23820

Follow Up By: Matt M - Monday, Jun 30, 2003 at 15:37

Monday, Jun 30, 2003 at 15:37

Phil, The original designers of the L300 would have spent months calculating the best compromise for that vehicle with engine power, gearing, revs and load.

If we change ANYTHING it effects that overall package. But as we all know... sometimes these changes are what we set out to achieve and suit our individual requirements.

If you change you gearing, be it final drives, T/case or wheel dia, then it will effect the vehicles top speed, revs at any speed and load (fuel consumption).

If the 2600 has the amount of torque output that, at that standard gearing, with 31' tyres on then your economy will most likey be better..IF... So at cruising speed, with just enough throttle to keep you there you may find you are cruising better. But usually any increase in top end gearing is ALOT more load on the engine and will cause it to use more fuel even if it is doing less revs!! But you wont know for sure without doing the sums!

You would need to compare the weight of the vehicle and what final gear ratio it operated at and the speed it used to turn at, because this is what the manufacturer would have set it for, for optimal economy at tthat speed. eg 1000kg Sigma with 3.11 reduction at diff plus 1.08 over drive in fifth doing 90km would give a rev of say 3000rpm could have been the most efficient load on the engine, but make it push harder (taller wheels) and you will increase the load even though you drop revs!!! So most likely higher fule consumption!

I dare say the L300 is heavier and the 2600 isnt all that neck snapping to allow for a decrease in load!! Its not like you have put a V8 Chev in a landcruiser!!

So there are alot of variables and heaps of different ranges and conditions to compare fuel consumption and unless you know the exact dia of the final wheels, there wont be many out htere that could give you and accurate answer. But hopefully you understabnd the complexity of the question and why there are so many different answers from EXPERTS!

ps EXPERT (EX, as in past tense) (Spurt, is a drip under pressure)

Goodluck and enjoy, I think the L300 will end up a good little rig!
Matt.