hi went to shop to get bulbs for car, they where out of 2057, and the clerk siad i could substiutue a 1157, i asked him why and he siad? you could, well i went home minus bulbs and started thinking about lighting in cars, the other bulbs are pretty clear where they go but, some like 1156, 1157, 2057,3157, 3357, 3457?..and all the other numbers, where do they use them i mean i see the diffrence in mount aka bayonet, or new clip ins wont fit here or there, but a lot of them look pretty close and i wonder can you substitute..........its just one of those things that are so basic you never think about.......any info ...opions.thansk................................

1156, 1157, 2057,3157, 3357, 3457

1156, BU bulb, single filiment

1157, 2057 brake turn bulb, they can be interchanged. There is a very slight intensity differance. GM has not used 1157 in over 20 years.

3157, is a 2057 bulb with a bayonett mount, newer styly bulb.

don't remember the other two right now

http://www.donsbulbs.com

man that was quick, so i can use 1157 for 2057, thanks..."+" for both of you...........................

[This message has been edited by silver86se (edited 06-10-2004).]

What I've done ( i know it's in the archives somewhere) is went to european spec on all of my little bulbs. Here's the breakdown:

Tail - Turn Signal: 7528
side markers: w5w
back-up: stock 1156 I think

Headlamps are sylvania X-tra vision.... I'm happy with the brightness that's added all around!!