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HI ALL

I AM NEW TO AUTOMATICS AND WAS WANDERING WHAT THE O/D BUTTON IS FOR, I ASK THIS AS I AM WAITING TO FIND OWNERS MANUAL ON EBAY AS LOCAL LEXUS DEALER SAYS THAT THEY CANNOT GET ONE BECAUSE IT'S OUT OF PRINT.

CAN U ALSO TELL ME HOW MUCH FUEL IT HOLDS IN THE TANK.

THANKS

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over drive?

dunno how it works though......

as for fuel capacity, i dunno, but i'm sure a GS300 owner will soon be along to tell you

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The overdrive button basically allows the car to go into it's highest gear. For example, let's say you have a 4-speed auto, with the overdrive on it will use all 4 gears, if you switch it off, it will just go upto 3rd gear, you'll very rarely ever need to turn it off, only perhaps when coasting down a hill and a you want a bit of engine braking.

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Imported GS

O/D - Over Drive, this means you can hold the gear change longer. In normal mode, the auto box will change at a set rev for smooth change from one gear to another, with O/D on (will show an orange light on the dash) the gear change will happen closer to the rev limiter and then change into the next gear and then will hold in this gear til near the rev limiter again. Also if you want to use kick down while in low revs, you can use the O/D, save you having to floor the acc to bring in the kick down.

********WARNING*********

It's best to only use the O/D when over 60 MPH, reason - to much use of the O/D under 60 can cause increased wear in the clutch plates in the box shorting the life of the box, personally experiance talking here.

The cap of my tank is 75 Ltres, think it may be the same as a UK spec GS

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Being a Mk1 it has a three speed auto box the O/D button, when engaged gives you the equivalent of a fourth gear.....I always keep it on, and occasionally switch it off to slow down as this in effect drops the box down a gear..........If towing the O/D should be switched off

Fuel Capacity is 80 litres or 17.6 imperial Gallons

Hope this is of some help

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Thats odd Peter, works different on my motor. mine uses all 4 gears without the O/D. Sound like the G/B's are different on the imports to the UK GS

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Thats odd Peter, works different on my motor. mine uses all 4 gears without the O/D. Sound like the G/B's are different on the imports to the UK GS

If your's in a MKII then they have a 5 speed auto box which is why you get 4 gears with O/D off. If it's a MKI then your probably experiencing the torque converter lock-up which when looking at the rev counter makes it look like another gear change as the revs drop again.

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Got the Imported Aristo TT MK I James, it's got the 4 Speed Auto, if I press the O/D, the revs goto 6.5K before changing. Also as soon as I press the O/D during normal driving, the box drops down a gear. Just been out for a drive to check.

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Thats odd Peter, works different on my motor. mine uses all 4 gears without the O/D. Sound like the G/B's are different on the imports to the UK GS

Paul, as I understand it

The mk1GS has a three speed box and the mk2 a four speed, but the O/D, when engaged, gives the extra gear, so obviously the Aristo has a better spec

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I thought both the Import and UK spec GS used the same G/B, opps

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I thought both the Import and UK spec GS used the same G/B, opps

Paul, Linkey

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It's a 4 speed box, pressing the button which brings on the light on the dash board cancells 4th ( OD ) gear. It also brings in engine braking in the lower gears. Being an AUTOMATIC transmission it senses load by various means and selects the correct gear for the circumstances ( or as near to it as Mr T designed into it ). It's an electronically controlled box linked to the ECU so even engine temp could affect shifts or possibly stop 4th gear engagement if it was very cold until the car warmed up.

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The MK1 Aristo has a 4 speed box, L, 2, D and O/D.

With the O/D light on, it will only select L to D (1-3) won't affect gear change rpm, that's to do with with throttle position/load and ECT switch.

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Will double check over the W/E

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thanks for the info, i thought as much just wasn't sure.

bigjud

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Interesting thread this.....

I`m only going from memory as I haven`t even sat in my car for weeks but mine`s supposed to be a UK model MkII with the sport box option switch and I think my handbook said the O/D switch was an over-ride switch to allow you to still select a gear if there was a gearbox problem.

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I have found this thread to be interesting and at the same time confusing. It seems I have a non import Mk1 GS300 with an overdrive switch on the side of the gear selector and also a button next to the gear selector marked.....PWR/ECT/Normal

Anyone shed any light on what these switches do? I also have a lack of owners guide to help me so any ideas would be great.

Tony

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I have found this thread to be interesting and at the same time confusing. It seems I have a non import Mk1 GS300 with an overdrive switch on the side of the gear selector and also a button next to the gear selector marked.....PWR/ECT/Normal

Anyone shed any light on what these switches do? I also have a lack of owners guide to help me so any ideas would be great.

Tony

The pwr/ect switch is similar to "sport mode" buttons on cars like Rover 827si. If you engage pwr mode a green? light illuminates on the dash and the g/box changes up at higher revs.

When I had my Series 1 Sport I drove with O/D permanently on after the first couple of months experimenting. From what I remember the orange light on dash illuminated when O/D was off though, not when on. On the very rare occasions that I turned O/D off the light on the dash lit up showing "O/D OFF" in orange. It isn't really that dissimilar to O/D on the manual boxes back in the '60s.

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PWR - No difference at full throttle. Part throttle - revs higher before changing up and needs less throttle to cause a downchange. (I have found the effects of PWR to be much more noticeable on the 5-speed in my Mk2 GS300 than on the 4-speeds in the Mk1 Aristo and Soarer).

O/D - It's just 4th gear. Has no other effect. Called "overdrive" because the ratio is higher than 1:1. It's not like the overdrive on cars like the MGB where an electrically switched 2-speed gearbox was added to the gearbox output shaft in order to provide extra, higher, ratios in 3rd and top.

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Sport mode also improves throttle response and quickens gear changes. Car will be more eager to change to down when braking, entering corners ect. As said, 3 speed with OD off 4 with it on. Usefull for some light engine braking. If you have an Aristo with the optional TEMS suspension the sport button will also stiffen the rebound on the dampers. GS300 never had this unfortunately ;)

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