This is really not a X type specific topic, since I want to replace the tail light bulbs of all 3 Jaguars with cree LED's, but I figured I can get the answers I need from this group.

The main reason I want to do this is because both my XJS And E type have very powerful aftermarket fans installed. I would like to save as much power as I can from other sources like bulbs...and I would replace them in the X type too to be consistent.

So, for example, I am seeing these two types of RED1156 CREE bulbs:

http://pages.ebay.com/link/?nav=item...d=261542250802

http://pages.ebay.com/link/?nav=item...d=360910133406

One is 30w the other is 50w. (All U.S made)

My question is, are these pulling less than the stock bulbs? Is the wattage just referring to the equivalent of light they are emitting? If they are going to use more power than standard bulbs, then that defeats the intention. Yes I have googled it, I still don't get it.

I am not too old at 32, but this kind of stuff just doesn't sink in.

Thanks for any help ..

 

Spike, maybe I can shed some light on this subject. Please keep in mind that there is a lot of double talk about newer technology and you need to be looking for some key words.

First things first, you need to get past the double talk. Be looking for words like "may need to modify" or "equivolent". When you start talking about having to modify, this will normally not end good unless you know electronics pretty well. So, keep that in mind. I will use the 50W CREE lights that you mentioned as they are wanting you to install a resistor to help handle the extra current. WARNING!!!!!!!! DO NOT DO THIS!!!!!!! The wiring in your car is only meant to handle but so much current and this bulb is going to pull almost 3 times the current that your factory bulbs most likely pull. Now, I will use your other bulb (30W CREE) in that is says that it is a "30W equivolent". This is most likely the style you want as this bulb will output the same light as a 30W bulb, but pulling less power/current than what a 30W bulb would. This would most likely be the bulb that you want. BUT!!!!!! More information is needed.

Like you mention, you are worried about current and this is a number that you will want to know for both your factory bulbs and any bulb that you may think about installing. The more important number that you need to know is the "LUMEN RATING". Lumens is a measure of how much light you are getting out. In your case, you are wanting a bigger number for your new bulbs than what you currently have installed.

Head spinning yet? You will have to do lots of research to find the manufacturer numbers for the bulbs. Don't believe what may be posted on something like e-bay when it comes to these bulbs as they will say anything to get you to buy the bulb.

Just to add a final wrinkle to this. This only applies to turn signal bulbs or any bulb that flashes with the turn signals. You need to use a bulb that uses roughly the same amount of current as the stock bulb. I say this as the computer uses the current draw to determine how fast to flash the bulb. Low current, it will flash a lot faster. Higher current and it will flash slower.

So, you might be out of luck for the most part when it comes to the turn signals. But, with some research, you can probably get a lot of savings from tail lights, stop lights, reverse lights, etc.

If you have more questions, let me know. HOpefully I have given you enough to get going and be able to buy a bulb that will do what you are after.

 

Thanks so much Chris, that helps.

This is what confuses me::

50W CREE LED Extremely Bright High Power BAY15D 1157 2057 2357 7528 Brilliant Red Bulbs for Turn Signal Tail Brake Light for Cars Trucks Trailers Motorcycles RV - JDM ASTAR

This guy says that they operate at 10W..I send an email asking and the reply was that I "may" need a resistor because the LED's operate at a much lower voltage than what the car outputs.

 

Spike, if you are having to add a resistor to make the bulb work, then I would toss it out as it is not properly manufactured then to support use in a vehicle. It is well known what voltages any car will operate at (either 12.6 VDC or 13.7 VDC). So, if you have to modify the wiring to make it work for a simple "bulb replacement", there are bigger issues.

 

Looking over the info that they are posting on the site, they are playing with numbers. I only know that because of understanding electronics. They are saying that they are using ten 5W CREEs in the bulb. Hence where they are getting the "50W bulb". But, then they are saying that it only pulls 10W. That is like saying you have a 500 HP motor, but you never step on the gas to raise the power above 100 hp. Explaining it using the motor analogy so you can understand what is going on, does that even make sense why you would create something like that?

I can tell you why they did that. They are packing too much stuff into too small of a package and therefore, if you ran the lights at their full capacity, they would fail in no time flat due to creating too much heat.

This is where you need to ask them the lumen output. That is the real measure that you want to use to compare one bulb against another. With LEDs and CREEs this line can become very blurry. For example, I just created a bulb for in my house using LEDs that outputs around 2500 lumen, but only uses 10W of power. Granted, you buy a pre-made LED bulb and it will output 600 lumen for 15W. Now, I will admit that I am playing a power game and know how to make the LEDs output maximum brightness using less power. But, that is something that most of the manufacturers are not going to want to use because the average consumer only really cares about watts as they have been brainwashed into relating wattage to brightness. Not so with the modern day lighting option.

 

The resistor would be to keep idiot warning lights such as brake light out off as some cars sense the lack of wattage being used and assume one of the bulbs is out. Like Chris said for turns you would need a resistor in the system to make up for the loss of wattage or would need a flasher designed to operate on say 20w instead of 60w. I replaced all of my bulbs (except headlights) on my TVR as the LEDs are a bit brighter. I just bought chinese bulbs. Spent maybe 75 for all the bulbs. the dash ones were a bit pricey. Couldn't be happier and haven't replaced a bulb in 2 years now. Biggest problem I ran into is LEDs require a certain polarity and a lot of my wiring was backwards so I had to do a bit of work, would doubt that is the case on the X type though. Also, remember you need a color light for red and amber to work right.

 

I have 50W Cree LED sidelights and 80W Cree LED reversing lights, both sets are direct replacements and neither set flicker

2x 50W T10 W5W 501 194 CREE + SAMSUNG High Power Led Car White Light Bulbs | eBay

BK 1156P BA15S 80W Cree LED Brake/Turn Car Signal, Reverse Light Lamp Bulb White | eBay

Check the sidelights are round and 11mm dia as I got a pair where the tops were square and they didn't fit

 

I suppose the first ones (W5W) are unsuitable for side indicators, unless one has the original orange lenses? Then again, the last time I considered this I decided that I prefer the "fade in fade out" -blinking of the side indicators over the sharp on-off LEDs.

I'm however still considering replacing at least the reversing lights and the brake lights with LEDs. Is 1156P the same as P21W? The brake lights needs a P21/5W though...

 

Thanks for the replies guys!

Thermo, all the LED's I am looking at have 600 lumen or more. They all claim they consume less than the regular bulbs.

It seems like the 30w Crees are the way to go at this point. They provide more light and seem to be clear about their max output.

 

Remember LEDs start to loose lumens once you use the. their half life is around 7 years meaning the lumens will be 1/2 what they were new.

 

Hmh, I was going to edit my post but managed to post a new message instead.

Anyway, nice comparison video of traditional bulbs and LEDs in indicators: